Theorem mpteq1df 42393

Description: An equality theorem for the maps-to notation. (Contributed by Glauco Siliprandi, 23-Oct-2021.)

Hypotheses

Ref	Expression
mpteq1df.1	⊢ Ⅎ𝑥𝜑
mpteq1df.2	⊢ (𝜑 → 𝐴 = 𝐵)

Assertion

Ref	Expression
mpteq1df	⊢ (𝜑 → (𝑥 ∈ 𝐴 ↦ 𝐶) = (𝑥 ∈ 𝐵 ↦ 𝐶))

Proof of Theorem mpteq1df

Step	Hyp	Ref	Expression
1		mpteq1df.1	. . 3 ⊢ Ⅎ𝑥𝜑
2		mpteq1df.2	. . 3 ⊢ (𝜑 → 𝐴 = 𝐵)
3	1, 2	alrimi 2213	. 2 ⊢ (𝜑 → ∀𝑥 𝐴 = 𝐵)
4		eqid 2736	. . 3 ⊢ 𝐶 = 𝐶
5	4	rgenw 3063	. 2 ⊢ ∀𝑥 ∈ 𝐴 𝐶 = 𝐶
6		mpteq12f 5123	. 2 ⊢ ((∀𝑥 𝐴 = 𝐵 ∧ ∀𝑥 ∈ 𝐴 𝐶 = 𝐶) → (𝑥 ∈ 𝐴 ↦ 𝐶) = (𝑥 ∈ 𝐵 ↦ 𝐶))
7	3, 5, 6	sylancl 589	1 ⊢ (𝜑 → (𝑥 ∈ 𝐴 ↦ 𝐶) = (𝑥 ∈ 𝐵 ↦ 𝐶))

Syntax hints:   → wi 4  ∀wal 1541   = wceq 1543  Ⅎwnf 1791  ∀wral 3051   ↦ cmpt 5120

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1803  ax-4 1817  ax-5 1918  ax-6 1976  ax-7 2018  ax-8 2114  ax-9 2122  ax-10 2143  ax-12 2177  ax-ext 2708

This theorem depends on definitions:  df-bi 210  df-an 400  df-or 848  df-tru 1546  df-ex 1788  df-nf 1792  df-sb 2073  df-clab 2715  df-cleq 2728  df-clel 2809  df-ral 3056  df-opab 5102  df-mpt 5121

This theorem is referenced by:  smfliminflem  43978