Added DefaultParser

docs/syntax_v1.md

@@ -84,7 +84,7 @@ concept is_the_opposite:
         a, b
         
     test:
-        a.pre == not b.pre && a.post == b.post
+        a.pre == not b.pre && a.post == not b.post
       
 
 print all concepts

docs/syntax_v2.md

@@ -17,4 +17,23 @@ def concept a is a number as :
 
 --> adds concept a is a number
 --> add the pre condition to the concept a plus b
+```
+
+# Define a new concept in one line
+```
+def concept words
+def concept words [where whereclause] [as expression] [pre precond] [post postcond]
+```
+
+# Define a complicated concept
+```
+def concept 
+as:
+    ...
+where:
+    ...
+pre:
+    ...
+post:
+    ...
 ```

docs/syntax_v3.md

@@ -0,0 +1,17 @@
+```
+> "hello
+-> unfinished quote "
+> def concept unfinished quote q
+... where:
+...... q in ('"', '"')
+... desc:
+...... "Error detected by the default parser where the trailing quote is missing"
+... input = sheerka.last_input
+
+
+> when unfinished quote q as c:
+... add rule as:
+...... if q in sheerka.input:
+......... sheerka.resume(c, c.input + input)
+......... remove rule 
+```