muJSStatement (JSForLetIn _ _ _ (JSVarInitExpression id _) _ gen _ body)    = muForIn VariablePattern id gen body
muJSStatement (JSForLetIn _ _ _ (JSVarInitExpression id _) _ gen _ body)    = muForIn VariablePattern id gen body
muJSStatement (JSForLetIn _ _ _ (JSVarInitExpression id _) _ gen _ body)    = muForIn VariablePattern id gen body