final String head = functionCall.getHead().getText();
if (head.matches("Set|SetDelayed")) {
final PsiElement lhs = functionCall.getArgument(1);
if (lhs != null) {
final SetDefinitionSymbolVisitor visitor = new SetDefinitionSymbolVisitor(lhs);
lhs.accept(visitor);
cacheAssignedSymbols(visitor.getUnboundSymbols());
}
} else if (head.matches("TagSet|TagSetDelayed|SetAttributes|SetOptions")) {
final PsiElement arg1 = functionCall.getArgument(1);
if (arg1 instanceof Symbol) {