type instance IsExpr (TrendOp vn e) = IsVarName vn :&&: IsExpr e
type instance IsCommonExpr (TrendOp vn e) = IsVarName vn :&&: IsCommonExpr e
type instance IsIterativeExpr (TrendOp vn e) = IsVarName vn :&&: IsIterativeExpr e
type instance IsExpr (TrendOp vn e) = IsVarName vn :&&: IsExpr e
type instance IsCommonExpr (TrendOp vn e) = IsVarName vn :&&: IsCommonExpr e
type instance IsIterativeExpr (TrendOp vn e) = IsVarName vn :&&: IsIterativeExpr e