Theorem f1imaeq 7263

Description: Taking images under a one-to-one function preserves equality. (Contributed by Stefan O'Rear, 30-Oct-2014.)

Assertion

Ref	Expression
f1imaeq	⊢ ((𝐹:𝐴–1-1→𝐵 ∧ (𝐶 ⊆ 𝐴 ∧ 𝐷 ⊆ 𝐴)) → ((𝐹 “ 𝐶) = (𝐹 “ 𝐷) ↔ 𝐶 = 𝐷))

Proof of Theorem f1imaeq

Step	Hyp	Ref	Expression
1		f1imass 7262	. . 3 ⊢ ((𝐹:𝐴–1-1→𝐵 ∧ (𝐶 ⊆ 𝐴 ∧ 𝐷 ⊆ 𝐴)) → ((𝐹 “ 𝐶) ⊆ (𝐹 “ 𝐷) ↔ 𝐶 ⊆ 𝐷))
2		f1imass 7262	. . . 4 ⊢ ((𝐹:𝐴–1-1→𝐵 ∧ (𝐷 ⊆ 𝐴 ∧ 𝐶 ⊆ 𝐴)) → ((𝐹 “ 𝐷) ⊆ (𝐹 “ 𝐶) ↔ 𝐷 ⊆ 𝐶))
3	2	ancom2s 650	. . 3 ⊢ ((𝐹:𝐴–1-1→𝐵 ∧ (𝐶 ⊆ 𝐴 ∧ 𝐷 ⊆ 𝐴)) → ((𝐹 “ 𝐷) ⊆ (𝐹 “ 𝐶) ↔ 𝐷 ⊆ 𝐶))
4	1, 3	anbi12d 632	. 2 ⊢ ((𝐹:𝐴–1-1→𝐵 ∧ (𝐶 ⊆ 𝐴 ∧ 𝐷 ⊆ 𝐴)) → (((𝐹 “ 𝐶) ⊆ (𝐹 “ 𝐷) ∧ (𝐹 “ 𝐷) ⊆ (𝐹 “ 𝐶)) ↔ (𝐶 ⊆ 𝐷 ∧ 𝐷 ⊆ 𝐶)))
5		eqss 3979	. 2 ⊢ ((𝐹 “ 𝐶) = (𝐹 “ 𝐷) ↔ ((𝐹 “ 𝐶) ⊆ (𝐹 “ 𝐷) ∧ (𝐹 “ 𝐷) ⊆ (𝐹 “ 𝐶)))
6		eqss 3979	. 2 ⊢ (𝐶 = 𝐷 ↔ (𝐶 ⊆ 𝐷 ∧ 𝐷 ⊆ 𝐶))
7	4, 5, 6	3bitr4g 314	1 ⊢ ((𝐹:𝐴–1-1→𝐵 ∧ (𝐶 ⊆ 𝐴 ∧ 𝐷 ⊆ 𝐴)) → ((𝐹 “ 𝐶) = (𝐹 “ 𝐷) ↔ 𝐶 = 𝐷))

Syntax hints:   → wi 4   ↔ wb 206   ∧ wa 395   = wceq 1540   ⊆ wss 3931   “ cima 5662  –1-1→wf1 6533

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1795  ax-4 1809  ax-5 1910  ax-6 1967  ax-7 2008  ax-8 2111  ax-9 2119  ax-10 2142  ax-11 2158  ax-12 2178  ax-ext 2708  ax-sep 5271  ax-nul 5281  ax-pr 5407

This theorem depends on definitions:  df-bi 207  df-an 396  df-or 848  df-3an 1088  df-tru 1543  df-fal 1553  df-ex 1780  df-nf 1784  df-sb 2066  df-mo 2540  df-eu 2569  df-clab 2715  df-cleq 2728  df-clel 2810  df-ne 2934  df-ral 3053  df-rex 3062  df-rab 3421  df-v 3466  df-dif 3934  df-un 3936  df-in 3938  df-ss 3948  df-nul 4314  df-if 4506  df-sn 4607  df-pr 4609  df-op 4613  df-uni 4889  df-br 5125  df-opab 5187  df-id 5553  df-xp 5665  df-rel 5666  df-cnv 5667  df-co 5668  df-dm 5669  df-rn 5670  df-res 5671  df-ima 5672  df-iota 6489  df-fun 6538  df-fn 6539  df-f 6540  df-f1 6541  df-fv 6544

This theorem is referenced by:  f1imapss  7264  dfac12lem2  10164  hmeoimaf1o  23713  imasf1oxms  24433  isuspgrim0  47874  isuspgrimlem  47875  upgrimtrlslem2  47885  grimedg  47915