lojix/wam_prolog/src/main/com/thesett/aima/logic/fol/wam/compiler/PreCompiler.java
private void topLevelCheck(Term clause)
    {
        TermWalker walk = TermWalkers.positionalWalker(new TopLevelCheckVisitor(interner, symbolTable, null));
        walk.walk(clause);
    }
private void topLevelCheck(Term clause)
    {
        TermWalker walk = TermWalkers.positionalWalker(new TopLevelCheckVisitor(interner, symbolTable, null));
        walk.walk(clause);
    }
Finds and marks all functors within the clause that are considered to be top-level.

@param clause The clause to top-level check.