Metamath Proof Explorer


Theorem xrneq1

Description: Equality theorem for the range Cartesian product. (Contributed by Peter Mazsa, 16-Dec-2020)

Ref Expression
Assertion xrneq1 ( 𝐴 = 𝐵 → ( 𝐴𝐶 ) = ( 𝐵𝐶 ) )

Proof

Step Hyp Ref Expression
1 coeq2 ( 𝐴 = 𝐵 → ( ( 1st ↾ ( V × V ) ) ∘ 𝐴 ) = ( ( 1st ↾ ( V × V ) ) ∘ 𝐵 ) )
2 1 ineq1d ( 𝐴 = 𝐵 → ( ( ( 1st ↾ ( V × V ) ) ∘ 𝐴 ) ∩ ( ( 2nd ↾ ( V × V ) ) ∘ 𝐶 ) ) = ( ( ( 1st ↾ ( V × V ) ) ∘ 𝐵 ) ∩ ( ( 2nd ↾ ( V × V ) ) ∘ 𝐶 ) ) )
3 df-xrn ( 𝐴𝐶 ) = ( ( ( 1st ↾ ( V × V ) ) ∘ 𝐴 ) ∩ ( ( 2nd ↾ ( V × V ) ) ∘ 𝐶 ) )
4 df-xrn ( 𝐵𝐶 ) = ( ( ( 1st ↾ ( V × V ) ) ∘ 𝐵 ) ∩ ( ( 2nd ↾ ( V × V ) ) ∘ 𝐶 ) )
5 2 3 4 3eqtr4g ( 𝐴 = 𝐵 → ( 𝐴𝐶 ) = ( 𝐵𝐶 ) )