exprToPred path (Subscript subscriptee subscript_expr _) = do
    subscripteep <- exprToPred (path.subscripteeL) subscriptee
    subscript_exprp <- exprToPred (path.subscript_exprL) subscript_expr
    return $ pSubscript subscripteep subscript_exprp
exprToPred path (Subscript subscriptee subscript_expr _) = do
    subscripteep <- exprToPred (path.subscripteeL) subscriptee
    subscript_exprp <- exprToPred (path.subscript_exprL) subscript_expr
    return $ pSubscript subscripteep subscript_exprp
exprToPred path (Subscript subscriptee subscript_expr _) = do
    subscripteep <- exprToPred (path.subscripteeL) subscriptee
    subscript_exprp <- exprToPred (path.subscript_exprL) subscript_expr
    return $ pSubscript subscripteep subscript_exprp