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Metamath Proof Explorer

Theorem ofeq

Description: Equality theorem for function operation. (Contributed by Mario Carneiro, 20-Jul-2014)

Ref Expression
Assertion ofeq ( 𝑅 = 𝑆 → ∘f 𝑅 = ∘f 𝑆 )

Proof

Step Hyp Ref Expression
1 id ⊢ ( 𝑅 = 𝑆 → 𝑅 = 𝑆 )
2 1 ofeqd ⊢ ( 𝑅 = 𝑆 → ∘f 𝑅 = ∘f 𝑆 )