paOp
 = pgAlts [
            pgApply (\x -> (True, ExprVar x, x)) paVarop,
            pgApply (\x -> (True, ExprCon x, x)) paConop,
            pgApply (\x -> (True, ExprVar x, x)) paMinus
          ]
paOp
 = pgAlts [
            pgApply (\x -> (True, ExprVar x, x)) paVarop,
            pgApply (\x -> (True, ExprCon x, x)) paConop,
            pgApply (\x -> (True, ExprVar x, x)) paMinus
          ]
paOp
 = pgAlts [
            pgApply (\x -> (True, ExprVar x, x)) paVarop,
            pgApply (\x -> (True, ExprCon x, x)) paConop,
            pgApply (\x -> (True, ExprVar x, x)) paMinus
          ]