no goals
m n a b c d : ℤ
h₁ : a ≡ b [ZMOD n]
h₂ : a + c ≡ b + d [ZMOD n]
⊢ d - c = b + d - (a + c) - (b - a)
ring
m n a b c d : ℤ
h₁ : a ≡ b [ZMOD n]
h₂ : a + c ≡ b + d [ZMOD n]
this : d - c = b + d - (a + c) - (b - a)
⊢ n ∣ b + d - (a + c) - (b - a)
m n a b c d : ℤ
h₁ : a ≡ b [ZMOD n]
h₂ : a + c ≡ b + d [ZMOD n]
this : d - c = b + d - (a + c) - (b - a)
⊢ n ∣ d - c
rw [this]
no goals
m n a b c d : ℤ
h₁ : a ≡ b [ZMOD n]
h₂ : a + c ≡ b + d [ZMOD n]
this : d - c = b + d - (a + c) - (b - a)
⊢ n ∣ b + d - (a + c) - (b - a)
exact dvd_sub h₂.dvd h₁.dvd