Theorem feq3 6066

Description: Equality theorem for functions. (Contributed by NM, 1-Aug-1994.)

Assertion

Ref	Expression
feq3	⊢ (𝐴 = 𝐵 → (𝐹:𝐶⟶𝐴 ↔ 𝐹:𝐶⟶𝐵))

Proof of Theorem feq3

Step	Hyp	Ref	Expression
1		sseq2 3660	. . 3 ⊢ (𝐴 = 𝐵 → (ran 𝐹 ⊆ 𝐴 ↔ ran 𝐹 ⊆ 𝐵))
2	1	anbi2d 740	. 2 ⊢ (𝐴 = 𝐵 → ((𝐹 Fn 𝐶 ∧ ran 𝐹 ⊆ 𝐴) ↔ (𝐹 Fn 𝐶 ∧ ran 𝐹 ⊆ 𝐵)))
3		df-f 5930	. 2 ⊢ (𝐹:𝐶⟶𝐴 ↔ (𝐹 Fn 𝐶 ∧ ran 𝐹 ⊆ 𝐴))
4		df-f 5930	. 2 ⊢ (𝐹:𝐶⟶𝐵 ↔ (𝐹 Fn 𝐶 ∧ ran 𝐹 ⊆ 𝐵))
5	2, 3, 4	3bitr4g 303	1 ⊢ (𝐴 = 𝐵 → (𝐹:𝐶⟶𝐴 ↔ 𝐹:𝐶⟶𝐵))

Syntax hints:   → wi 4   ↔ wb 196   ∧ wa 383   = wceq 1523   ⊆ wss 3607  ran crn 5144   Fn wfn 5921  ⟶wf 5922

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1762  ax-4 1777  ax-5 1879  ax-6 1945  ax-7 1981  ax-9 2039  ax-10 2059  ax-11 2074  ax-12 2087  ax-13 2282  ax-ext 2631

This theorem depends on definitions:  df-bi 197  df-or 384  df-an 385  df-tru 1526  df-ex 1745  df-nf 1750  df-sb 1938  df-clab 2638  df-cleq 2644  df-clel 2647  df-in 3614  df-ss 3621  df-f 5930

This theorem is referenced by:  feq23  6067  feq3d  6070  fun2  6105  fconstg  6130  f1eq3  6136  mapvalg  7909  mapsn  7941  cantnff  8609  axdc4uz  12823  supcvg  14632  lmff  21153  txcn  21477  lmmbr  23102  iscmet3  23137  dvcnvrelem2  23826  itgsubstlem  23856  umgrislfupgr  26063  usgrislfuspgr  26124  wlkv0  26603  isgrpo  27479  vciOLD  27544  isvclem  27560  nmop0h  28978  sitgaddlemb  30538  sitmcl  30541  cvmliftlem15  31406  mtyf  31575  matunitlindflem1  33535  sdclem1  33669  k0004lem1  38762  mapsnd  39702  stoweidlem57  40592