cases b
case mk
b c : ℤω
x✝ y✝ : ℤ
⊢ toℂ (mul { x := x✝, y := y✝ } b) = toℂ { x := x✝, y := y✝ } * toℂ b
case mk.mk
c : ℤω
x✝¹ y✝¹ x✝ y✝ : ℤ
⊢ toℂ (mul { x := x✝¹, y := y✝¹ } { x := x✝, y := y✝ }) = toℂ { x := x✝¹, y := y✝¹ } * toℂ { x := x✝, y := y✝ }