Metamath Proof Explorer


Theorem rnghmresel

Description: An element of the non-unital ring homomorphisms restricted to a subset of non-unital rings is a non-unital ring homomorphisms. (Contributed by AV, 9-Mar-2020)

Ref Expression
Hypothesis rnghmresel.h ( 𝜑𝐻 = ( RngHomo ↾ ( 𝐵 × 𝐵 ) ) )
Assertion rnghmresel ( ( 𝜑 ∧ ( 𝑋𝐵𝑌𝐵 ) ∧ 𝐹 ∈ ( 𝑋 𝐻 𝑌 ) ) → 𝐹 ∈ ( 𝑋 RngHomo 𝑌 ) )

Proof

Step Hyp Ref Expression
1 rnghmresel.h ( 𝜑𝐻 = ( RngHomo ↾ ( 𝐵 × 𝐵 ) ) )
2 1 adantr ( ( 𝜑 ∧ ( 𝑋𝐵𝑌𝐵 ) ) → 𝐻 = ( RngHomo ↾ ( 𝐵 × 𝐵 ) ) )
3 2 oveqd ( ( 𝜑 ∧ ( 𝑋𝐵𝑌𝐵 ) ) → ( 𝑋 𝐻 𝑌 ) = ( 𝑋 ( RngHomo ↾ ( 𝐵 × 𝐵 ) ) 𝑌 ) )
4 ovres ( ( 𝑋𝐵𝑌𝐵 ) → ( 𝑋 ( RngHomo ↾ ( 𝐵 × 𝐵 ) ) 𝑌 ) = ( 𝑋 RngHomo 𝑌 ) )
5 4 adantl ( ( 𝜑 ∧ ( 𝑋𝐵𝑌𝐵 ) ) → ( 𝑋 ( RngHomo ↾ ( 𝐵 × 𝐵 ) ) 𝑌 ) = ( 𝑋 RngHomo 𝑌 ) )
6 3 5 eqtrd ( ( 𝜑 ∧ ( 𝑋𝐵𝑌𝐵 ) ) → ( 𝑋 𝐻 𝑌 ) = ( 𝑋 RngHomo 𝑌 ) )
7 6 eleq2d ( ( 𝜑 ∧ ( 𝑋𝐵𝑌𝐵 ) ) → ( 𝐹 ∈ ( 𝑋 𝐻 𝑌 ) ↔ 𝐹 ∈ ( 𝑋 RngHomo 𝑌 ) ) )
8 7 biimp3a ( ( 𝜑 ∧ ( 𝑋𝐵𝑌𝐵 ) ∧ 𝐹 ∈ ( 𝑋 𝐻 𝑌 ) ) → 𝐹 ∈ ( 𝑋 RngHomo 𝑌 ) )