Top level where expressions for nested rules are applied to both the nested and parent rule

[Sean Kauffman]

The following rules break

D :- ((A BEFORE B) BEFORE C) where A.foo
D :- ((A BEFORE B) BEFORE C) where (A.foo = B.bar)

The problem is that the expression references only the nested rule. The result is that the restriction is correctly applied to that rule but also incorrectly applied to the top level rule.

[Sean Kauffman]

Fix issue #27 by adding a check to omit generating any expression when the where clause is completely unrelated to the rule

→ <<cset 59c9ef515316>>