Metamath Proof Explorer


Theorem functhinclem2

Description: Lemma for functhinc . (Contributed by Zhi Wang, 1-Oct-2024)

Ref Expression
Hypotheses functhinclem2.x ( 𝜑𝑋𝐵 )
functhinclem2.y ( 𝜑𝑌𝐵 )
functhinclem2.1 ( 𝜑 → ∀ 𝑥𝐵𝑦𝐵 ( ( ( 𝐹𝑥 ) 𝐽 ( 𝐹𝑦 ) ) = ∅ → ( 𝑥 𝐻 𝑦 ) = ∅ ) )
Assertion functhinclem2 ( 𝜑 → ( ( ( 𝐹𝑋 ) 𝐽 ( 𝐹𝑌 ) ) = ∅ → ( 𝑋 𝐻 𝑌 ) = ∅ ) )

Proof

Step Hyp Ref Expression
1 functhinclem2.x ( 𝜑𝑋𝐵 )
2 functhinclem2.y ( 𝜑𝑌𝐵 )
3 functhinclem2.1 ( 𝜑 → ∀ 𝑥𝐵𝑦𝐵 ( ( ( 𝐹𝑥 ) 𝐽 ( 𝐹𝑦 ) ) = ∅ → ( 𝑥 𝐻 𝑦 ) = ∅ ) )
4 simpl ( ( 𝑥 = 𝑋𝑦 = 𝑌 ) → 𝑥 = 𝑋 )
5 4 fveq2d ( ( 𝑥 = 𝑋𝑦 = 𝑌 ) → ( 𝐹𝑥 ) = ( 𝐹𝑋 ) )
6 simpr ( ( 𝑥 = 𝑋𝑦 = 𝑌 ) → 𝑦 = 𝑌 )
7 6 fveq2d ( ( 𝑥 = 𝑋𝑦 = 𝑌 ) → ( 𝐹𝑦 ) = ( 𝐹𝑌 ) )
8 5 7 oveq12d ( ( 𝑥 = 𝑋𝑦 = 𝑌 ) → ( ( 𝐹𝑥 ) 𝐽 ( 𝐹𝑦 ) ) = ( ( 𝐹𝑋 ) 𝐽 ( 𝐹𝑌 ) ) )
9 8 eqeq1d ( ( 𝑥 = 𝑋𝑦 = 𝑌 ) → ( ( ( 𝐹𝑥 ) 𝐽 ( 𝐹𝑦 ) ) = ∅ ↔ ( ( 𝐹𝑋 ) 𝐽 ( 𝐹𝑌 ) ) = ∅ ) )
10 oveq12 ( ( 𝑥 = 𝑋𝑦 = 𝑌 ) → ( 𝑥 𝐻 𝑦 ) = ( 𝑋 𝐻 𝑌 ) )
11 10 eqeq1d ( ( 𝑥 = 𝑋𝑦 = 𝑌 ) → ( ( 𝑥 𝐻 𝑦 ) = ∅ ↔ ( 𝑋 𝐻 𝑌 ) = ∅ ) )
12 9 11 imbi12d ( ( 𝑥 = 𝑋𝑦 = 𝑌 ) → ( ( ( ( 𝐹𝑥 ) 𝐽 ( 𝐹𝑦 ) ) = ∅ → ( 𝑥 𝐻 𝑦 ) = ∅ ) ↔ ( ( ( 𝐹𝑋 ) 𝐽 ( 𝐹𝑌 ) ) = ∅ → ( 𝑋 𝐻 𝑌 ) = ∅ ) ) )
13 12 rspc2gv ( ( 𝑋𝐵𝑌𝐵 ) → ( ∀ 𝑥𝐵𝑦𝐵 ( ( ( 𝐹𝑥 ) 𝐽 ( 𝐹𝑦 ) ) = ∅ → ( 𝑥 𝐻 𝑦 ) = ∅ ) → ( ( ( 𝐹𝑋 ) 𝐽 ( 𝐹𝑌 ) ) = ∅ → ( 𝑋 𝐻 𝑌 ) = ∅ ) ) )
14 13 imp ( ( ( 𝑋𝐵𝑌𝐵 ) ∧ ∀ 𝑥𝐵𝑦𝐵 ( ( ( 𝐹𝑥 ) 𝐽 ( 𝐹𝑦 ) ) = ∅ → ( 𝑥 𝐻 𝑦 ) = ∅ ) ) → ( ( ( 𝐹𝑋 ) 𝐽 ( 𝐹𝑌 ) ) = ∅ → ( 𝑋 𝐻 𝑌 ) = ∅ ) )
15 1 2 3 14 syl21anc ( 𝜑 → ( ( ( 𝐹𝑋 ) 𝐽 ( 𝐹𝑌 ) ) = ∅ → ( 𝑋 𝐻 𝑌 ) = ∅ ) )