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