typeToTypeExpr (Arrow t1 t2) = TEArrow (typeToTypeExpr t1) (typeToTypeExpr t2)
typeToTypeExpr (Arrow t1 t2) = TEArrow (typeToTypeExpr t1) (typeToTypeExpr t2)
typeToTypeExpr (Arrow t1 t2) = TEArrow (typeToTypeExpr t1) (typeToTypeExpr t2)