diff --git a/src/cache/CacheManager.py b/src/cache/CacheManager.py
index ff9cfaf..783b4e9 100644
--- a/src/cache/CacheManager.py
+++ b/src/cache/CacheManager.py
@@ -259,3 +259,11 @@ class CacheManager:
                     self.caches[cache_name].cache.init_from(content)
 
         return self
+
+    def reset(self, cache_only):
+        """For unit test speed enhancement"""
+        self.cache_only = cache_only
+        self.caches.clear()
+        self.concept_caches.clear()
+        self.is_dirty = False
+
diff --git a/src/core/builtin_concepts.py b/src/core/builtin_concepts.py
index 162f458..b973ffa 100644
--- a/src/core/builtin_concepts.py
+++ b/src/core/builtin_concepts.py
@@ -59,6 +59,8 @@ class BuiltinConcepts(Enum):
     CHICKEN_AND_EGG = "chicken and egg"  # infinite recursion when declaring concept
     ISA = "is a"  # builtin concept to express that a concept is an instance of another one
     EXPLANATION = "explanation"
+    PRECEDENCE = "precedence"  # use to set priority among concepts when parsing
+    ASSOCIATIVITY = "associativity"  # use to set priority among concepts when parsing
 
     NODE = "node"
     GENERIC_NODE = "generic node"
diff --git a/src/core/concept.py b/src/core/concept.py
index dcc3a92..08798a2 100644
--- a/src/core/concept.py
+++ b/src/core/concept.py
@@ -342,20 +342,30 @@ class Concept:
 
         return self
 
-    def add_prop(self, concept_key, value):
+    def add_prop(self, property_name, value):
         """
         Set or add a behaviour to a concept
         A behaviour is a value from another concept (ex BuiltinConcepts.ISA
-        :param concept_key: Concept key
+        :param property_name: Concept key
         :param value:
         :return:
         """
-        if concept_key in self.metadata.props:
-            self.metadata.props[concept_key].add(value)
+        if property_name in self.metadata.props:
+            self.metadata.props[property_name].add(value)
         else:
-            self.metadata.props[concept_key] = {value}  # a set
+            self.metadata.props[property_name] = {value}  # a set
         return self
 
+    def set_prop(self, property_name, value):
+        """
+        Set a behaviour to a concept
+        A behaviour is a value from another concept (ex BuiltinConcepts.ISA
+        :param property_name: Concept key
+        :param value:
+        :return:
+        """
+        self.metadata.props[property_name] = value
+
     def get_prop(self, concept_key):
         """
         Gets a behaviour of a concept
diff --git a/src/core/sheerka/ExecutionContext.py b/src/core/sheerka/ExecutionContext.py
index 838314c..73eef3a 100644
--- a/src/core/sheerka/ExecutionContext.py
+++ b/src/core/sheerka/ExecutionContext.py
@@ -3,7 +3,7 @@ import time
 
 from core.builtin_concepts import BuiltinConcepts
 from core.concept import Concept
-from core.sheerka.Services.SheerkaExecute import NO_MATCH
+from core.sheerka.services.SheerkaExecute import NO_MATCH
 from core.sheerka_logger import get_logger
 from sdp.sheerkaDataProvider import Event
 
diff --git a/src/core/sheerka/Sheerka.py b/src/core/sheerka/Sheerka.py
index 41ca7f0..f83c1d2 100644
--- a/src/core/sheerka/Sheerka.py
+++ b/src/core/sheerka/Sheerka.py
@@ -12,14 +12,14 @@ from core.builtin_concepts import BuiltinConcepts, ErrorConcept, ReturnValueConc
     UnknownConcept
 from core.concept import Concept, ConceptParts, PROPERTIES_FOR_NEW
 from core.sheerka.ExecutionContext import ExecutionContext
-from core.sheerka.Services.SheerkaCreateNewConcept import SheerkaCreateNewConcept
-from core.sheerka.Services.SheerkaDump import SheerkaDump
-from core.sheerka.Services.SheerkaEvaluateConcept import SheerkaEvaluateConcept
-from core.sheerka.Services.SheerkaExecute import SheerkaExecute
-from core.sheerka.Services.SheerkaHistoryManager import SheerkaHistoryManager
-from core.sheerka.Services.SheerkaModifyConcept import SheerkaModifyConcept
-from core.sheerka.Services.SheerkaSetsManager import SheerkaSetsManager
-from core.sheerka.Services.SheerkaVariableManager import SheerkaVariableManager
+from core.sheerka.services.SheerkaCreateNewConcept import SheerkaCreateNewConcept
+from core.sheerka.services.SheerkaDump import SheerkaDump
+from core.sheerka.services.SheerkaEvaluateConcept import SheerkaEvaluateConcept
+from core.sheerka.services.SheerkaExecute import SheerkaExecute
+from core.sheerka.services.SheerkaHistoryManager import SheerkaHistoryManager
+from core.sheerka.services.SheerkaModifyConcept import SheerkaModifyConcept
+from core.sheerka.services.SheerkaSetsManager import SheerkaSetsManager
+from core.sheerka.services.SheerkaVariableManager import SheerkaVariableManager
 from core.sheerka_logger import console_handler
 from printer.SheerkaPrinter import SheerkaPrinter
 from sdp.sheerkaDataProvider import SheerkaDataProvider, Event
@@ -72,6 +72,8 @@ class Sheerka(Concept):
         self.sdp: SheerkaDataProvider = None  # SheerkaDataProvider
         self.cache_manager = CacheManager(cache_only)
 
+        self.services = {}  # sheerka plugins
+
         self.builtin_cache = {}  # cache for builtin concepts
         self.parsers = {}  # cache for builtin parsers
         self.evaluators = []  # cache for builtin evaluators
@@ -114,6 +116,20 @@ class Sheerka(Concept):
     def concepts_grammars(self):
         return self.cache_manager.caches[self.CONCEPTS_GRAMMARS_ENTRY].cache
 
+    def bind_service_method(self, instance, method, as_name=None):
+        """
+        Bind service method to sheerka instance for ease to use
+        :param instance:
+        :param method:
+        :param as_name:
+        :return:
+        """
+        if as_name is None:
+            as_name = method.__name__
+
+        bound_method = method.__get__(instance, instance.__class__)
+        setattr(self, as_name, bound_method)
+
     def initialize(self, root_folder: str = None, save_execution_context=True):
         """
         Starting Sheerka
@@ -139,6 +155,7 @@ class Sheerka(Concept):
                 if self.sdp.first_time:
                     self.first_time_initialisation(exec_context)
 
+                self.initialize_services()
                 self.initialize_builtin_parsers()
                 self.initialize_builtin_evaluators()
                 self.initialize_builtin_concepts()
@@ -212,6 +229,21 @@ class Sheerka(Concept):
         self.cache_manager.put(self.CONCEPTS_KEYS_ENTRY, self.USER_CONCEPTS_KEYS, 1000)
         self.variable_handler.record(context, self.name, "save_execution_context", True)
 
+    def initialize_services(self):
+        """
+        Introspect to find services and bind them
+        :return:
+        """
+        self.init_log.debug("Initializing services")
+
+        core.utils.import_module_and_sub_module('core.sheerka.services')
+        base_class = "core.sheerka.services.sheerka_service.BaseService"
+        for service in core.utils.get_sub_classes("core.sheerka.services", base_class):
+            instance = service(self)
+            if hasattr(instance, "initialize"):
+                instance.initialize()
+            self.services[service.NAME] = instance
+
     def initialize_builtin_concepts(self):
         """
         Initializes the builtin concepts
@@ -300,8 +332,14 @@ class Sheerka(Concept):
         self.cache_manager.put(self.RESOLVED_CONCEPTS_BY_FIRST_KEYWORD_ENTRY, False, res.body)
 
     def reset(self, cache_only=False):
-        self.cache_manager.clear()
-        self.cache_manager.cache_only = cache_only
+        if self.cache_manager.cache_only != cache_only:
+            self.cache_manager.reset(cache_only)
+            self.initialize_caching()
+            for service in self.services.values():
+                if hasattr(service, "initialize"):
+                    service.initialize()
+        else:
+            self.cache_manager.clear()
         self.printer_handler.reset()
         self.sdp.reset()
 
diff --git a/src/core/sheerka/services/SheerkaComparisonManager.py b/src/core/sheerka/services/SheerkaComparisonManager.py
new file mode 100644
index 0000000..e0d3633
--- /dev/null
+++ b/src/core/sheerka/services/SheerkaComparisonManager.py
@@ -0,0 +1,206 @@
+from dataclasses import dataclass
+
+from cache.Cache import Cache
+from cache.ListCache import ListCache
+from core.builtin_concepts import BuiltinConcepts
+from core.sheerka.services.sheerka_service import ServiceObj, BaseService
+
+
+@dataclass
+class ComparisonObj(ServiceObj):
+    """
+    Order to store
+    """
+    property: str  # property to compare
+    a: int  # id of concept a
+    b: int  # id of concept b
+    op: str  # comparison operation
+    context: str = "#"  # context when the comparison is right
+
+
+class SheerkaComparisonManager(BaseService):
+    """
+    Manage partitioning of concepts
+    """
+    NAME = "ComparisonManager"
+    COMPARISON_ENTRY = "Comparison"
+    RESOLVED_COMPARISON_ENTRY = "Resolved_Comparison"
+
+    def __init__(self, sheerka):
+        super().__init__(sheerka)
+
+    @staticmethod
+    def _compute_key(prop_name, comparison_context):
+        return f"{prop_name}|{comparison_context}"
+
+    @staticmethod
+    def _compute_weights(comparison_objs):
+        """
+        For every element in greater_than_s, give it a weight
+        if weight(a) > weight(b) it means that a > b
+        :param comparison_objs: list of greater than objects
+        :return:
+        """
+
+        values = {}
+        for comparison_obj in comparison_objs:
+            values[comparison_obj.a] = 1
+            values[comparison_obj.b] = 1
+
+        for _ in range(len(comparison_objs)):
+            for comparison_obj in comparison_objs:
+                if comparison_obj.op == ">":
+                    values[comparison_obj.a] = values[comparison_obj.b] + 1
+                else:
+                    values[comparison_obj.b] = values[comparison_obj.a] + 1
+
+        return values
+
+    @staticmethod
+    def _get_partition(weighted_concepts):
+
+        res = {}
+        for k, v in weighted_concepts.items():
+            res.setdefault(v, []).append(k)
+        return res
+
+    def _inner_add_comparison(self, comparison_obj):
+        key = self._compute_key(comparison_obj.property, comparison_obj.context)
+        previous = self.sheerka.cache_manager.get(self.COMPARISON_ENTRY, key)
+
+        new = previous.copy() if previous else []
+        new.append(comparison_obj)
+
+        cycles = self.detect_cycles(new)
+        if cycles:
+            concepts_in_cycle = [self.sheerka.get_by_id(c) for c in cycles]
+            chicken_an_egg = self.sheerka.new(BuiltinConcepts.CHICKEN_AND_EGG, body=concepts_in_cycle)
+            return self.sheerka.ret(self.NAME, False, chicken_an_egg)
+
+        self.sheerka.cache_manager.put(self.RESOLVED_COMPARISON_ENTRY, key, self._compute_weights(new))
+        self.sheerka.cache_manager.put(self.COMPARISON_ENTRY, key, comparison_obj)
+
+        return self.sheerka.ret(self.NAME, True, self.sheerka.new(BuiltinConcepts.SUCCESS))
+
+    def initialize(self):
+        cache = ListCache(default=lambda k: self.sheerka.sdp.get(self.COMPARISON_ENTRY, k))
+        self.sheerka.cache_manager.register_cache(self.COMPARISON_ENTRY, cache, True, True)
+
+        cache = Cache()
+        self.sheerka.cache_manager.register_cache(self.RESOLVED_COMPARISON_ENTRY, cache, persist=False)
+
+        self.sheerka.bind_service_method(self, SheerkaComparisonManager.is_greater_than)
+        self.sheerka.bind_service_method(self, SheerkaComparisonManager.is_less_than)
+        self.sheerka.bind_service_method(self, SheerkaComparisonManager.get_partition)
+        self.sheerka.bind_service_method(self, SheerkaComparisonManager.get_concepts_weights)
+
+    def is_greater_than(self, context, prop_name, concept_a, concept_b, comparison_context="#"):
+        """
+        Records that the property of concept a is greater than concept b's one
+        :param context:
+        :param prop_name:
+        :param concept_a:
+        :param concept_b:
+        :param comparison_context:
+        :return:
+        """
+        context.log(f"Setting concept {concept_a} is greater than {concept_b}", who=self.NAME)
+
+        event_digest = context.event.get_digest()
+        comparison_obj = ComparisonObj(event_digest, prop_name, concept_a.id, concept_b.id, ">", comparison_context)
+        return self._inner_add_comparison(comparison_obj)
+
+    def is_less_than(self, context, prop_name, concept_a, concept_b, comparison_context="#"):
+        """
+        Records that the property of concept a is lesser than concept b's one
+        :param context:
+        :param prop_name:
+        :param concept_a:
+        :param concept_b:
+        :param comparison_context:
+        :return:
+        """
+        context.log(f"Setting concept {concept_a} is less than {concept_b}", who=self.NAME)
+
+        event_digest = context.event.get_digest()
+        comparison_obj = ComparisonObj(event_digest, prop_name, concept_a.id, concept_b.id, "<", comparison_context)
+        return self._inner_add_comparison(comparison_obj)
+
+    def get_partition(self, prop_name, comparison_context="#"):
+        weighted_concept = self.get_concepts_weights(prop_name, comparison_context)
+
+        return self._get_partition(weighted_concept)
+
+    def get_concepts_weights(self, prop_name, comparison_context="#"):
+        weighted_concept = self.sheerka.cache_manager.get(
+            self.RESOLVED_COMPARISON_ENTRY,
+            self._compute_key(prop_name, comparison_context))
+
+        if weighted_concept is None:
+            key = self._compute_key(prop_name, comparison_context)
+            entries = self.sheerka.cache_manager.get(self.COMPARISON_ENTRY, key)
+
+            if entries is None:
+                return {}
+            else:
+                weighted_concept = self._compute_weights(entries)
+                self.sheerka.cache_manager.put(self.RESOLVED_COMPARISON_ENTRY, key, weighted_concept)
+
+        return weighted_concept
+
+    @staticmethod
+    def detect_cycles(comparison_objs):
+        """
+        # Thanks to Divyanshu Mehta for contributing this code
+        # https://www.geeksforgeeks.org/detect-cycle-in-a-graph/?ref=lbp
+        :param comparison_objs:
+        :return:
+        """
+        latest = comparison_objs[-1]
+        if latest.op == "=":
+            return None
+
+        def get_graph_and_vertices():
+            _graph = {}
+            _vertices = set()
+            for obj in comparison_objs:
+                if obj.op == "=":
+                    continue
+
+                _vertices.add(obj.a)
+                _vertices.add(obj.b)
+                if obj.op == ">":
+                    _graph.setdefault(obj.a, []).append(obj.b)
+                else:
+                    _graph.setdefault(obj.b, []).append(obj.a)
+            return _graph, _vertices
+
+        def is_cyclic(v):
+            # Mark current node as visited and
+            # adds to recursion stack
+            visited[v] = True
+            rec_stack[v] = True
+
+            # Recur for all neighbours
+            # if any neighbour is visited and in
+            # recStack then graph is cyclic
+            if v in graph:
+                for neighbour in graph[v]:
+                    if not visited[neighbour]:
+                        if is_cyclic(neighbour):
+                            return True
+                    elif rec_stack[neighbour]:
+                        return True
+
+            # The node needs to be poped from
+            # recursion stack before function ends
+            rec_stack[v] = False
+            return False
+
+        graph, vertices = get_graph_and_vertices()
+        visited = {k: False for k in vertices}
+        rec_stack = {k: False for k in vertices}
+
+        if is_cyclic(latest.a):  # only need to check from the latest add, since the graph was not cyclic before
+            return [k for k, v in rec_stack.items() if v]
+        return None
diff --git a/src/core/sheerka/Services/SheerkaCreateNewConcept.py b/src/core/sheerka/services/SheerkaCreateNewConcept.py
similarity index 97%
rename from src/core/sheerka/Services/SheerkaCreateNewConcept.py
rename to src/core/sheerka/services/SheerkaCreateNewConcept.py
index 7d8f159..4fdb74f 100644
--- a/src/core/sheerka/Services/SheerkaCreateNewConcept.py
+++ b/src/core/sheerka/services/SheerkaCreateNewConcept.py
@@ -14,7 +14,7 @@ class SheerkaCreateNewConcept:
 
     def __init__(self, sheerka):
         self.sheerka = sheerka
-        self.logger_name = self.create_new_concept.__name__
+        self.logger_name = "CreateNewConcept"
         self.bnp = core.utils.get_class(BASE_NODE_PARSER_CLASS)  # BaseNodeParser
 
     def create_new_concept(self, context, concept: Concept):
diff --git a/src/core/sheerka/Services/SheerkaDump.py b/src/core/sheerka/services/SheerkaDump.py
similarity index 100%
rename from src/core/sheerka/Services/SheerkaDump.py
rename to src/core/sheerka/services/SheerkaDump.py
diff --git a/src/core/sheerka/Services/SheerkaEvaluateConcept.py b/src/core/sheerka/services/SheerkaEvaluateConcept.py
similarity index 97%
rename from src/core/sheerka/Services/SheerkaEvaluateConcept.py
rename to src/core/sheerka/services/SheerkaEvaluateConcept.py
index 15cdac9..4b00f7d 100644
--- a/src/core/sheerka/Services/SheerkaEvaluateConcept.py
+++ b/src/core/sheerka/services/SheerkaEvaluateConcept.py
@@ -11,7 +11,7 @@ CONCEPT_EVALUATION_STEPS = [
 class SheerkaEvaluateConcept:
     def __init__(self, sheerka):
         self.sheerka = sheerka
-        self.logger_name = self.evaluate_concept.__name__
+        self.logger_name = "EvaluateConcept"
 
     @staticmethod
     def infinite_recursion_detected(context, concept):
@@ -88,7 +88,7 @@ class SheerkaEvaluateConcept:
             if source.strip() == "":
                 concept.compiled[part_key] = DoNotResolve(source)
             else:
-                with context.push(desc=f"Initializing compiled for {part_key}") as sub_context:
+                with context.push(desc=f"Initializing *compiled* for {part_key}") as sub_context:
                     sub_context.add_inputs(source=source)
                     to_parse = self.sheerka.ret(context.who, True,
                                                 self.sheerka.new(BuiltinConcepts.USER_INPUT, body=source))
@@ -107,11 +107,11 @@ class SheerkaEvaluateConcept:
             if default_value.strip() == "":
                 concept.compiled[var_name] = DoNotResolve(default_value)
             else:
-                with context.push(desc=f"Initializing AST for property {var_name}") as sub_context:
+                with context.push(desc=f"Initializing *compiled* for property {var_name}") as sub_context:
                     sub_context.add_inputs(source=default_value)
                     to_parse = self.sheerka.ret(context.who, True,
                                                 self.sheerka.new(BuiltinConcepts.USER_INPUT, body=default_value))
-                    res = self.sheerka.execute(context, to_parse, steps)
+                    res = self.sheerka.execute(sub_context, to_parse, steps)
                     only_success = only_successful(sub_context, res)
                     concept.compiled[var_name] = only_success.body.body if is_only_successful(only_success) else res
                     sub_context.add_values(return_values=res)
diff --git a/src/core/sheerka/Services/SheerkaExecute.py b/src/core/sheerka/services/SheerkaExecute.py
similarity index 100%
rename from src/core/sheerka/Services/SheerkaExecute.py
rename to src/core/sheerka/services/SheerkaExecute.py
diff --git a/src/core/sheerka/Services/SheerkaHistoryManager.py b/src/core/sheerka/services/SheerkaHistoryManager.py
similarity index 100%
rename from src/core/sheerka/Services/SheerkaHistoryManager.py
rename to src/core/sheerka/services/SheerkaHistoryManager.py
diff --git a/src/core/sheerka/Services/SheerkaModifyConcept.py b/src/core/sheerka/services/SheerkaModifyConcept.py
similarity index 96%
rename from src/core/sheerka/Services/SheerkaModifyConcept.py
rename to src/core/sheerka/services/SheerkaModifyConcept.py
index 8ab8de0..f640d17 100644
--- a/src/core/sheerka/Services/SheerkaModifyConcept.py
+++ b/src/core/sheerka/services/SheerkaModifyConcept.py
@@ -4,7 +4,7 @@ from core.builtin_concepts import BuiltinConcepts
 class SheerkaModifyConcept:
     def __init__(self, sheerka):
         self.sheerka = sheerka
-        self.logger_name = self.modify_concept.__name__
+        self.logger_name = "ModifyConcept"
 
     def modify_concept(self, context, concept):
         old_version = self.sheerka.get_by_id(concept.id)
diff --git a/src/core/sheerka/Services/SheerkaSetsManager.py b/src/core/sheerka/services/SheerkaSetsManager.py
similarity index 99%
rename from src/core/sheerka/Services/SheerkaSetsManager.py
rename to src/core/sheerka/services/SheerkaSetsManager.py
index 8d188a2..732aca1 100644
--- a/src/core/sheerka/Services/SheerkaSetsManager.py
+++ b/src/core/sheerka/services/SheerkaSetsManager.py
@@ -9,7 +9,7 @@ GROUP_PREFIX = 'All_'
 class SheerkaSetsManager:
     def __init__(self, sheerka):
         self.sheerka = sheerka
-        self.logger_name = self.add_concept_to_set.__name__
+        self.logger_name = "SetsManager"
 
     def set_isa(self, context, concept, concept_set):
         """
diff --git a/src/core/sheerka/Services/SheerkaVariableManager.py b/src/core/sheerka/services/SheerkaVariableManager.py
similarity index 85%
rename from src/core/sheerka/Services/SheerkaVariableManager.py
rename to src/core/sheerka/services/SheerkaVariableManager.py
index f7b3f6d..3fa2e95 100644
--- a/src/core/sheerka/Services/SheerkaVariableManager.py
+++ b/src/core/sheerka/services/SheerkaVariableManager.py
@@ -1,20 +1,21 @@
 from dataclasses import dataclass
 from typing import List
 
+from core.sheerka.services.sheerka_service import ServiceObj
+
 
 @dataclass
-class Variable:
+class Variable(ServiceObj):
     """
     Variable to store
     """
-    event_id: str  # event where the variable is modified
     who: str  # who is the modifier
     key: str  # key of the variable
     value: object  # value
     parents: List[str]  # previous references of the variable (Note that there should be only one parent)
 
     def get_key(self):
-        return f"{self.who}.{self.key}"
+        return f"{self.who}|{self.key}"
 
 
 class SheerkaVariableManager:
@@ -36,11 +37,11 @@ class SheerkaVariableManager:
         self.sheerka.cache_manager.put(self.sheerka.VARIABLES_ENTRY, variable.get_key(), variable)
 
     def load(self, who, key):
-        variable = self.sheerka.cache_manager.get(self.sheerka.VARIABLES_ENTRY, who + "." + key)
+        variable = self.sheerka.cache_manager.get(self.sheerka.VARIABLES_ENTRY, who + "|" + key)
         if variable is None:
             return None
 
         return variable.value
 
     def delete(self, context, who, key):
-        self.sheerka.cache_manager.delete(self.sheerka.VARIABLES_ENTRY, who + "." + key)
+        self.sheerka.cache_manager.delete(self.sheerka.VARIABLES_ENTRY, who + "|" + key)
diff --git a/src/core/sheerka/Services/__init__.py b/src/core/sheerka/services/__init__.py
similarity index 100%
rename from src/core/sheerka/Services/__init__.py
rename to src/core/sheerka/services/__init__.py
diff --git a/src/core/sheerka/services/sheerka_service.py b/src/core/sheerka/services/sheerka_service.py
new file mode 100644
index 0000000..52eb297
--- /dev/null
+++ b/src/core/sheerka/services/sheerka_service.py
@@ -0,0 +1,14 @@
+from dataclasses import dataclass
+
+
+@dataclass
+class ServiceObj:
+    event_id: str  # event where the object is created / modified
+
+
+class BaseService:
+    """
+    Base class for services
+    """
+    def __init__(self, sheerka):
+        self.sheerka = sheerka
diff --git a/src/core/utils.py b/src/core/utils.py
index 1732e90..a718228 100644
--- a/src/core/utils.py
+++ b/src/core/utils.py
@@ -29,6 +29,14 @@ def sysarg_to_string(argv):
     return result
 
 
+def get_all_loaded_modules(prefix):
+    import sys
+    if prefix:
+        return [m for m in sys.modules.keys() if m.startswith(prefix)]
+    else:
+        return sys.modules.keys()
+
+
 def get_class(qname):
     """
     Loads a class from its full qualified name
@@ -117,12 +125,31 @@ def get_classes_from_package(package_name):
 def init_package_import(package_name):
     pkg = __import__(package_name)
     prefix = pkg.__name__ + "."
+    # prefix = package_name + "."
     for (module_loader, name, ispkg) in pkgutil.iter_modules(pkg.__path__, prefix):
         importlib.import_module(name)
+    importlib.import_module(package_name)
+
+
+def import_module_and_sub_module(module_name):
+    """
+    Import the module, and one sub level
+    :param module_name:
+    :return:
+    """
+    mod = get_module(module_name)
+    for (module_loader, name, ispkg) in pkgutil.iter_modules(mod.__path__, module_name + "."):
+        importlib.import_module(name)
 
 
 def get_sub_classes(package_name, base_class):
-    base_class = get_class(base_class) if isinstance(base_class, str) else base_class
+    def _get_class(name):
+        modname, _, clsname = name.rpartition('.')
+        mod = importlib.import_module(modname)
+        cls = getattr(mod, clsname)
+        return cls
+
+    base_class = _get_class(base_class) if isinstance(base_class, str) else base_class
     all_class = set(base_class.__subclasses__()).union(
         [s for c in base_class.__subclasses__() for s in get_sub_classes(package_name, c)])
 
diff --git a/src/evaluators/PythonEvaluator.py b/src/evaluators/PythonEvaluator.py
index d49074a..076eacf 100644
--- a/src/evaluators/PythonEvaluator.py
+++ b/src/evaluators/PythonEvaluator.py
@@ -70,7 +70,8 @@ class PythonEvaluator(OneReturnValueEvaluator):
             "concepts": context.sheerka.dump_handler.dump_concepts,
             "history": context.sheerka.dump_handler.dump_history,
             "state": context.sheerka.dump_handler.dump_state,
-            "Concept": core.concept.Concept
+            "Concept": core.concept.Concept,
+            "BuiltinConcepts": core.builtin_concepts.BuiltinConcepts,
         }
         if context.obj:
             context.log(f"Concept '{context.obj}' is in context. Adding it and its properties to locals.", self.name)
diff --git a/src/parsers/AtomNodeParser.py b/src/parsers/AtomNodeParser.py
index e1090db..8585ee5 100644
--- a/src/parsers/AtomNodeParser.py
+++ b/src/parsers/AtomNodeParser.py
@@ -241,7 +241,6 @@ class AtomNodeParser(BaseNodeParser):
         :param concept:
         :return:
         """
-        # return len(concept.metadata.props) == 0 or concept.metadata.definition_type == DEFINITION_TYPE_BNF
         return len(concept.metadata.variables) == 0 and concept.metadata.definition_type != DEFINITION_TYPE_BNF
 
     def get_concepts_sequences(self):
@@ -325,6 +324,9 @@ class AtomNodeParser(BaseNodeParser):
                 continue
 
             for node in parser_helper.sequence:
+                if isinstance(node, ConceptNode):
+                    if len(node.concept.metadata.variables) > 0:
+                        node.concept.metadata.is_evaluated = True  # Do not try to evaluate those concepts
                 node.tokens = self.tokens[node.start:node.end + 1]
                 node.fix_source()
 
diff --git a/src/parsers/SyaNodeParser.py b/src/parsers/SyaNodeParser.py
index 4c65245..581c427 100644
--- a/src/parsers/SyaNodeParser.py
+++ b/src/parsers/SyaNodeParser.py
@@ -952,107 +952,17 @@ class SyaNodeParser(BaseNodeParser):
                 sya_concept_def.precedence = sya_def[0]
             if sya_def[1] is not None:
                 sya_concept_def.associativity = sya_def[1]
+
+        if parser.sheerka:
+            concept_weight = parser.sheerka.get_concepts_weights(BuiltinConcepts.PRECEDENCE)
+            if concept.id in concept_weight:
+                sya_concept_def.precedence = concept_weight[concept.id]
+
+        if associativity := concept.get_prop(BuiltinConcepts.ASSOCIATIVITY):
+            sya_concept_def.associativity = SyaAssociativity(associativity)
+
         return sya_concept_def
 
-    # def reset_parser(self, context, text):
-    #     self.context = context
-    #     self.sheerka = context.sheerka
-    #     self.text = text
-    #
-    #     try:
-    #         self.tokens = list(self.get_input_as_tokens(text))
-    #     except LexerError as e:
-    #         self.add_error(self.sheerka.new(BuiltinConcepts.ERROR, body=e), False)
-    #         return False
-    #
-    #     self.token = None
-    #     self.pos = -1
-    #     return True
-    #
-    # def add_error(self, error, next_token=True):
-    #     self.error_sink.append(error)
-    #     if next_token:
-    #         self.next_token()
-    #     return error
-    #
-    # def get_token(self) -> Token:
-    #     return self.token
-    #
-    # def next_token(self, skip_whitespace=True):
-    #     if self.token and self.token.type == TokenKind.EOF:
-    #         return False
-    #
-    #     self.pos += 1
-    #     self.token = self.tokens[self.pos]
-    #
-    #     if skip_whitespace:
-    #         while self.token.type == TokenKind.WHITESPACE or self.token.type == TokenKind.NEWLINE:
-    #             self.pos += 1
-    #             self.token = self.tokens[self.pos]
-    #
-    #     return self.token.type != TokenKind.EOF
-
-    # def initialize(self, context, concepts=None, sya_definitions=None):
-    #     self.context = context
-    #     self.sheerka = context.sheerka
-    #
-    #     if sya_definitions:
-    #         self.sya_definitions = sya_definitions
-    #
-    #     if concepts:
-    #         for concept in concepts:
-    #             keywords = concept.key.split()
-    #             for keyword in keywords:
-    #                 if keyword.startswith(VARIABLE_PREFIX):
-    #                     continue
-    #
-    #                 self.concepts_by_first_keyword.setdefault(keyword, []).append(concept.id)
-    #                 break
-    #
-    #     return self.sheerka.ret(self.name, True, self.concepts_by_first_keyword)
-    #
-    # def get_concepts(self, token):
-    #     """
-    #     Tries to find if there are concepts that match the value of the token
-    #     :param token:
-    #     :return:
-    #     """
-    #
-    #     if token.type == TokenKind.STRING:
-    #         name = token.value[1:-1]
-    #     elif token.type == TokenKind.KEYWORD:
-    #         name = token.value.value
-    #     else:
-    #         name = token.value
-    #
-    #     result = []
-    #     if name in self.concepts_by_first_keyword:
-    #         for concept_id in self.concepts_by_first_keyword[name]:
-    #
-    #             concept = self.sheerka.get_by_id(concept_id)
-    #
-    #             if len(concept.metadata.props) == 0:
-    #                 # only concepts that has parameter (refuse atoms)
-    #                 # Note that this test is needed if the definition of the concept has changed
-    #                 continue
-    #
-    #             if concept.metadata.definition_type == DEFINITION_TYPE_BNF:
-    #                 # bnf definitions are not supposed to be managed by this parser
-    #                 continue
-    #
-    #             sya_concept_def = SyaConceptDef(concept)
-    #             if concept.id in self.sya_definitions:
-    #                 sya_def = self.sya_definitions[concept.id]
-    #                 if sya_def[0] is not None:
-    #                     sya_concept_def.precedence = sya_def[0]
-    #                 if sya_def[1] is not None:
-    #                     sya_concept_def.associativity = sya_def[1]
-    #
-    #             result.append(sya_concept_def)
-    #         return result
-    #
-    #     return None
-
     def infix_to_postfix(self, context, text):
         """
         Implementing Shunting Yard Algorithm
diff --git a/src/sdp/readme.md b/src/sdp/readme.md
index a36597f..43895e8 100644
--- a/src/sdp/readme.md
+++ b/src/sdp/readme.md
@@ -13,7 +13,7 @@
 - C : concept (with history management)
 - D : concept definitions (no history management)
 - R : executionContext ('R' stands for Result or ReturnValue, no history management)
-- V : variable (from pickle)
+- O : ServiceObj (from pickle)
 
 ## How concepts are serialized ?
 - get the id of the concept
diff --git a/src/sdp/sheerkaSerializer.py b/src/sdp/sheerkaSerializer.py
index f47007a..d8457b7 100644
--- a/src/sdp/sheerkaSerializer.py
+++ b/src/sdp/sheerkaSerializer.py
@@ -60,7 +60,7 @@ class Serializer:
         self.register(ConceptSerializer())
         self.register(DictionarySerializer())
         self.register(ExecutionContextSerializer())
-        self.register(VariableSerializer())
+        self.register(ServiceObjSerializer())
 
     def register(self, serializer):
         """
@@ -288,11 +288,13 @@ class ExecutionContextSerializer(BaseSerializer):
         return obj
 
 
-class VariableSerializer(PickleSerializer):
+class ServiceObjSerializer(PickleSerializer):
+    base_class = get_class("core.sheerka.services.sheerka_service.ServiceObj")
+
     def __init__(self):
         super().__init__(
-            lambda obj: get_full_qualified_name(obj) == "core.sheerka.Services.SheerkaVariableManager.Variable",
-            "V",
+            lambda obj: isinstance(obj, self.base_class),
+            "O",
             1)
 
 #
diff --git a/tests/core/test_SheerkaComparisonManager.py b/tests/core/test_SheerkaComparisonManager.py
new file mode 100644
index 0000000..9cdac4d
--- /dev/null
+++ b/tests/core/test_SheerkaComparisonManager.py
@@ -0,0 +1,149 @@
+import pytest
+from core.builtin_concepts import BuiltinConcepts
+from core.sheerka.services.SheerkaComparisonManager import SheerkaComparisonManager, ComparisonObj
+
+from tests.TestUsingMemoryBasedSheerka import TestUsingMemoryBasedSheerka
+
+
+class TestSheerkaGreaterThanManager(TestUsingMemoryBasedSheerka):
+    def test_i_can_add_a_is_greater_than(self):
+        sheerka, context, one, two = self.init_concepts("one", "two", cache_only=False)
+        service = sheerka.services[SheerkaComparisonManager.NAME]
+
+        res = service.is_greater_than(context, "prop_name", two, one)
+        assert res.status
+        assert sheerka.isinstance(res.body, BuiltinConcepts.SUCCESS)
+
+        in_cache = sheerka.cache_manager.get(SheerkaComparisonManager.COMPARISON_ENTRY, "prop_name|#")
+        assert in_cache == [ComparisonObj(context.event.get_digest(), "prop_name", two.id, one.id, ">", "#")]
+
+        weighted = sheerka.cache_manager.get(SheerkaComparisonManager.RESOLVED_COMPARISON_ENTRY, "prop_name|#")
+        assert weighted == {"1001": 1, "1002": 2}
+
+        # I can commit
+        sheerka.cache_manager.commit(context)
+        in_db = sheerka.sdp.get(SheerkaComparisonManager.COMPARISON_ENTRY, "prop_name|#")
+        assert in_db == [ComparisonObj(context.event.get_digest(), "prop_name", two.id, one.id, ">", "#")]
+
+    def test_i_can_add_a_is_less_than(self):
+        sheerka, context, one, two = self.init_concepts("one", "two", cache_only=False)
+        service = sheerka.services[SheerkaComparisonManager.NAME]
+
+        res = service.is_less_than(context, "prop_name", one, two)
+        assert res.status
+        assert sheerka.isinstance(res.body, BuiltinConcepts.SUCCESS)
+
+        in_cache = sheerka.cache_manager.get(SheerkaComparisonManager.COMPARISON_ENTRY, "prop_name|#")
+        assert in_cache == [ComparisonObj(context.event.get_digest(), "prop_name", one.id, two.id, "<", "#")]
+
+        weighted = sheerka.cache_manager.get(SheerkaComparisonManager.RESOLVED_COMPARISON_ENTRY, "prop_name|#")
+        assert weighted == {"1001": 1, "1002": 2}
+
+        # I can commit
+        sheerka.cache_manager.commit(context)
+        in_db = sheerka.sdp.get(SheerkaComparisonManager.COMPARISON_ENTRY, "prop_name|#")
+        assert in_db == [ComparisonObj(context.event.get_digest(), "prop_name", one.id, two.id, "<", "#")]
+
+    def test_i_can_add_multiples_constraints(self):
+        sheerka, context, one, two, three, four = self.init_concepts("one", "two", "three", "four", cache_only=False)
+        service = sheerka.services[SheerkaComparisonManager.NAME]
+
+        service.is_greater_than(context, "prop_name", two, one)
+        service.is_greater_than(context, "prop_name", three, two)
+
+        in_cache = sheerka.cache_manager.get(SheerkaComparisonManager.COMPARISON_ENTRY, "prop_name|#")
+        assert in_cache == [
+            ComparisonObj(context.event.get_digest(), "prop_name", two.id, one.id, ">", "#"),
+            ComparisonObj(context.event.get_digest(), "prop_name", three.id, two.id, ">", "#")
+        ]
+
+        # I can commit
+        sheerka.cache_manager.commit(context)
+        in_db = sheerka.sdp.get(SheerkaComparisonManager.COMPARISON_ENTRY, "prop_name|#")
+        assert in_db == [
+            ComparisonObj(context.event.get_digest(), "prop_name", two.id, one.id, ">", "#"),
+            ComparisonObj(context.event.get_digest(), "prop_name", three.id, two.id, ">", "#")
+        ]
+
+        sheerka.cache_manager.clear(SheerkaComparisonManager.COMPARISON_ENTRY)  # reset the cache
+
+        service.is_greater_than(context, "prop_name", four, three)
+        in_cache = sheerka.cache_manager.get(SheerkaComparisonManager.COMPARISON_ENTRY, "prop_name|#")
+        assert in_cache == [
+            ComparisonObj(context.event.get_digest(), "prop_name", two.id, one.id, ">", "#"),
+            ComparisonObj(context.event.get_digest(), "prop_name", three.id, two.id, ">", "#"),
+            ComparisonObj(context.event.get_digest(), "prop_name", four.id, three.id, ">", "#"),
+        ]
+
+        weighted = sheerka.cache_manager.get(SheerkaComparisonManager.RESOLVED_COMPARISON_ENTRY, "prop_name|#")
+        assert weighted == {"1001": 1, "1002": 2, "1003": 3, "1004": 4}
+
+    @pytest.mark.parametrize("entries, expected", [
+        (["two > one"], {'1001': 1, '1002': 2}),
+        (["one < two"], {'1001': 1, '1002': 2}),
+        (["three > two", "one < two"], {'1001': 1, '1002': 2, '1003': 3}),
+        (["three > one", "one < two"], {'1001': 1, '1002': 2, '1003': 2}),
+    ])
+    def test_i_can_get_concept_weight(self, entries, expected):
+        sheerka, context, *concepts = self.init_concepts("one", "two", "three")
+        service = sheerka.services[SheerkaComparisonManager.NAME]
+        concepts_map = dict(zip(["one", "two", "three", "four", "five", "six"], concepts))
+
+        for entry in entries:
+            if ">" in entry:
+                a, b = [concepts_map[e.strip()] for e in entry.split(">")]
+                service.is_greater_than(context, "prop_name", a, b)
+            else:
+                a, b = [concepts_map[e.strip()] for e in entry.split("<")]
+                service.is_less_than(context, "prop_name", a, b)
+
+        assert service.get_concepts_weights("prop_name") == expected
+
+    def test_i_can_get_partition(self):
+        sheerka, context, one, two, three = self.init_concepts("one", "two", "three")
+        service = sheerka.services[SheerkaComparisonManager.NAME]
+
+        service.is_greater_than(context, "prop_name", two, one)
+        service.is_less_than(context, "prop_name", two, three)
+
+        res = service.get_partition("prop_name")
+
+        assert res == {
+            1: ["1001"],
+            2: ["1002"],
+            3: ["1003"],
+        }
+
+    def test_i_can_detect_chicken_and_egg(self):
+        sheerka, context, one, two = self.init_concepts("one", "two")
+        service = sheerka.services[SheerkaComparisonManager.NAME]
+
+        service.is_greater_than(context, "prop_name", two, one)
+        res = service.is_greater_than(context, "prop_name", one, two)
+
+        assert not res.status
+        assert sheerka.isinstance(res.body, BuiltinConcepts.CHICKEN_AND_EGG)
+        assert set(res.body.body) == {one, two}
+
+    def test_i_can_detect_more_complex_chicken_and_egg(self):
+        sheerka, context, one, two, three, four, five = self.init_concepts("one", "two", "three", "four", "five")
+        service = sheerka.services[SheerkaComparisonManager.NAME]
+
+        service.is_greater_than(context, "prop_name", two, one)
+        service.is_greater_than(context, "prop_name", five, four)
+        service.is_greater_than(context, "prop_name", four, three)
+        service.is_greater_than(context, "prop_name", five, two)
+
+        res = service.is_greater_than(context, "prop_name", two, one)
+        assert res.status
+
+        res = service.is_greater_than(context, "prop_name", one, five)
+
+        assert not res.status
+        assert sheerka.isinstance(res.body, BuiltinConcepts.CHICKEN_AND_EGG)
+        assert set(res.body.body) == {one, two, five}
+
+    def test_methods_are_correctly_bound(self):
+        sheerka, context, one, two = self.init_concepts("one", "two")
+        res = sheerka.is_greater_than(context, "prop_name", two, one)
+        assert res.status
diff --git a/tests/core/test_SheerkaHistoryManager.py b/tests/core/test_SheerkaHistoryManager.py
index b1dbee6..90e8878 100644
--- a/tests/core/test_SheerkaHistoryManager.py
+++ b/tests/core/test_SheerkaHistoryManager.py
@@ -1,4 +1,4 @@
-from core.sheerka.Services.SheerkaHistoryManager import hist
+from core.sheerka.services.SheerkaHistoryManager import hist
 from tests.TestUsingMemoryBasedSheerka import TestUsingMemoryBasedSheerka
 
 
diff --git a/tests/core/test_SheerkaVariableManager.py b/tests/core/test_SheerkaVariableManager.py
index bba3cb7..b8982f4 100644
--- a/tests/core/test_SheerkaVariableManager.py
+++ b/tests/core/test_SheerkaVariableManager.py
@@ -16,8 +16,8 @@ class TestSheerkaVariable(TestUsingMemoryBasedSheerka):
         # I can persist in db
         sheerka.cache_manager.commit(context)
 
-        assert sheerka.sdp.exists(Sheerka.VARIABLES_ENTRY, "TestSheerkaVariable.my_variable")
-        loaded = sheerka.sdp.get(Sheerka.VARIABLES_ENTRY, "TestSheerkaVariable.my_variable")
+        assert sheerka.sdp.exists(Sheerka.VARIABLES_ENTRY, "TestSheerkaVariable|my_variable")
+        loaded = sheerka.sdp.get(Sheerka.VARIABLES_ENTRY, "TestSheerkaVariable|my_variable")
         assert loaded.event_id == context.event.get_digest()
         assert loaded.key == "my_variable"
         assert loaded.value == 1
diff --git a/tests/core/test_sheerka.py b/tests/core/test_sheerka.py
index 36ed7a0..e889117 100644
--- a/tests/core/test_sheerka.py
+++ b/tests/core/test_sheerka.py
@@ -16,6 +16,13 @@ class ConceptWithGetObjValue(Concept):
 
 class TestSheerkaUsingMemoryBasedSheerka(TestUsingMemoryBasedSheerka):
 
+    def test_i_can_initialize_services(self):
+        sheerka = self.get_sheerka()
+
+        assert len(sheerka.services) > 0
+        assert None not in sheerka.services
+        assert "ComparisonManager" in sheerka.services  # test at least one service
+
     def test_i_can_initialize_builtin_parsers(self):
         sheerka = self.get_sheerka()
 
diff --git a/tests/non_reg/test_sheerka_non_reg.py b/tests/non_reg/test_sheerka_non_reg.py
index 85b1e45..ae13c66 100644
--- a/tests/non_reg/test_sheerka_non_reg.py
+++ b/tests/non_reg/test_sheerka_non_reg.py
@@ -855,6 +855,24 @@ as:
         assert res[0].status
         assert res[0].body == 64
 
+    def test_concepts_parsed_by_atom_parser_must_not_be_evaluated(self):
+        definitions = [
+            "def concept mult from a mult b as a * b",
+            "def concept a mult b as a * b",
+        ]
+
+        sheerka = self.init_scenario(definitions)
+
+        res = sheerka.evaluate_user_input("eval mult")
+
+        assert res[0].status
+        assert isinstance(res[0].body, Concept)
+
+        # res = sheerka.evaluate_user_input("eval a mult b")
+        #
+        # assert res[0].status
+        # assert isinstance(res[0].body, Concept)
+
 
 class TestSheerkaNonRegFile(TestUsingFileBasedSheerka):
     def test_i_can_def_several_concepts(self):
diff --git a/tests/parsers/test_AtomsParser.py b/tests/parsers/test_AtomsParser.py
index 3d0e35e..0ffca77 100644
--- a/tests/parsers/test_AtomsParser.py
+++ b/tests/parsers/test_AtomsParser.py
@@ -1,22 +1,25 @@
 import pytest
 from core.builtin_concepts import BuiltinConcepts
-from core.concept import Concept
+from core.concept import Concept, DEFINITION_TYPE_DEF
 from parsers.AtomNodeParser import AtomNodeParser
-from parsers.BaseNodeParser import cnode, utnode, CNC, scnode, SCN
+from parsers.BaseNodeParser import cnode, utnode, CNC, SCN
 
 from tests.TestUsingMemoryBasedSheerka import TestUsingMemoryBasedSheerka
 from tests.parsers.parsers_utils import compute_expected_array
 
 
 class TestAtomsParser(TestUsingMemoryBasedSheerka):
-    def init_parser(self, my_map, create_new=False, singleton=True):
+    def init_parser(self, my_map, create_new=False, singleton=True, use_sheerka=False):
         sheerka, context, *updated_concepts = self.init_concepts(
             *my_map.values(),
             create_new=create_new,
             singleton=singleton)
 
-        parser = AtomNodeParser()
-        parser.init_from_concepts(context, updated_concepts)
+        if use_sheerka:
+            parser = AtomNodeParser(sheerka=sheerka)
+        else:
+            parser = AtomNodeParser()
+            parser.init_from_concepts(context, updated_concepts)
 
         return sheerka, context, parser
 
@@ -32,15 +35,20 @@ class TestAtomsParser(TestUsingMemoryBasedSheerka):
         ("foo", ["foo"]),
         ("foo bar", ["foo", "bar"]),
         ("foo bar twenties", ["foo", "bar", "twenties"]),
+        # ("plus", ["plus"]),
+        # ("++", ["++"]),
+        # ("a++ foo", ["++", "foo"]),
     ])
     def test_i_can_parse_simple_sequences(self, text, expected):
         concepts_map = {
             "foo": Concept("foo"),
             "bar": Concept("bar"),
+            "plus": Concept("a plus b").def_var("a").def_var("b"),
+            "++": Concept("++", definition="a++", definition_type=DEFINITION_TYPE_DEF).def_var("a"),
             "twenties": Concept("twenties", definition="'twenty' ('one'|'two')=unit").def_var("unit"),
         }
 
-        sheerka, context, parser = self.init_parser(concepts_map)
+        sheerka, context, parser = self.init_parser(concepts_map, create_new=True, use_sheerka=True)
         res = parser.parse(context, text)
         wrapper = res.body
         lexer_nodes = res.body.body
@@ -276,3 +284,27 @@ class TestAtomsParser(TestUsingMemoryBasedSheerka):
         expected_array = compute_expected_array(concepts_map, text, expected)
         assert sheerka.isinstance(wrapper, BuiltinConcepts.PARSER_RESULT)
         assert lexer_nodes == expected_array
+
+    @pytest.mark.parametrize("text, expected_is_evaluated", [
+        ("foo",  False),
+        ("bar", False ),
+        ("twenties", True),
+        ("plus", True),
+        # ("plus", ["plus"]),
+        # ("++", ["++"]),
+        # ("a++ foo", ["++", "foo"]),
+    ])
+    def test_concepts_with_variables_must_not_be_evaluated(self, text, expected_is_evaluated):
+        concepts_map = {
+            "foo": Concept("foo"),
+            "bar": Concept("bar", body="'bar'"),
+            "plus": Concept("plus", definition="a plus b", definition_type=DEFINITION_TYPE_DEF).def_var("a").def_var("b"),
+            "twenties": Concept("twenties", definition="'twenty' ('one'|'two')=unit").def_var("unit"),
+        }
+
+        sheerka, context, parser = self.init_parser(concepts_map, create_new=True, use_sheerka=True)
+        res = parser.parse(context, text)
+        lexer_nodes = res.body.body
+
+        assert res.status
+        assert lexer_nodes[0].concept.metadata.is_evaluated == expected_is_evaluated
diff --git a/tests/parsers/test_SyaNodeParser.py b/tests/parsers/test_SyaNodeParser.py
index 682a3e9..e1c7499 100644
--- a/tests/parsers/test_SyaNodeParser.py
+++ b/tests/parsers/test_SyaNodeParser.py
@@ -1,6 +1,7 @@
 import pytest
 from core.builtin_concepts import BuiltinConcepts
 from core.concept import Concept, CC
+from core.sheerka.services.SheerkaComparisonManager import SheerkaComparisonManager
 from core.tokenizer import Tokenizer
 from parsers.BaseNodeParser import utnode, ConceptNode, cnode, short_cnode, UnrecognizedTokensNode, \
     SCWC, CNC, UTN
@@ -48,10 +49,20 @@ class TestSyaNodeParser(TestUsingMemoryBasedSheerka):
             create_new=True,
             init_from_sheerka=True)
 
-        TestSyaNodeParser.sheerka.force_sya_def(context, [
-            (cmap["plus"].id, 5, SyaAssociativity.Right),
-            (cmap["mult"].id, 10, SyaAssociativity.Right),
-            (cmap["minus"].id, 10, SyaAssociativity.Right)])
+        cmap["plus"].set_prop(BuiltinConcepts.ASSOCIATIVITY, "right")
+        cmap["mult"].set_prop(BuiltinConcepts.ASSOCIATIVITY, "right")
+        cmap["minus"].set_prop(BuiltinConcepts.ASSOCIATIVITY, "right")
+        TestSyaNodeParser.sheerka.services[SheerkaComparisonManager.NAME].is_greater_than(context,
+                                                                                          BuiltinConcepts.PRECEDENCE,
+                                                                                          cmap["mult"], cmap["plus"])
+        TestSyaNodeParser.sheerka.services[SheerkaComparisonManager.NAME].is_greater_than(context,
+                                                                                          BuiltinConcepts.PRECEDENCE,
+                                                                                          cmap["mult"], cmap["minus"])
+
+        # TestSyaNodeParser.sheerka.force_sya_def(context, [
+        #     (cmap["plus"].id, 5, SyaAssociativity.Right),
+        #     (cmap["mult"].id, 10, SyaAssociativity.Right),
+        #     (cmap["minus"].id, 5, SyaAssociativity.Right)])
 
     def init_parser(self,
                     my_concepts_map=None,