Set: pp::colors Set: pp::unicode Imported 'Int' Assumed: x Type ℤ → ℤ → ℤ x1 + x2 ℤ → ℤ x1 + x1 + x1 + x2 + x2 ℤ definition sum1 : ℤ := x1 + x1 + x1 + x2 + x2 x1 + x1 + x1 + x2 + x2 Assumed: y