Theorem fv2prc 6391

Description: A function's value at a function's value at a proper class is the empty set. (Contributed by AV, 8-Apr-2021.)

Assertion

Ref	Expression
fv2prc	⊢ (¬ 𝐴 ∈ V → ((𝐹‘𝐴)‘𝐵) = ∅)

Proof of Theorem fv2prc

Step	Hyp	Ref	Expression
1		fvprc 6348	. . 3 ⊢ (¬ 𝐴 ∈ V → (𝐹‘𝐴) = ∅)
2	1	fveq1d 6356	. 2 ⊢ (¬ 𝐴 ∈ V → ((𝐹‘𝐴)‘𝐵) = (∅‘𝐵))
3		0fv 6390	. 2 ⊢ (∅‘𝐵) = ∅
4	2, 3	syl6eq 2811	1 ⊢ (¬ 𝐴 ∈ V → ((𝐹‘𝐴)‘𝐵) = ∅)

Syntax hints:  ¬ wn 3   → wi 4   = wceq 1632   ∈ wcel 2140  Vcvv 3341  ∅c0 4059  ‘cfv 6050

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1871  ax-4 1886  ax-5 1989  ax-6 2055  ax-7 2091  ax-8 2142  ax-9 2149  ax-10 2169  ax-11 2184  ax-12 2197  ax-13 2392  ax-ext 2741  ax-nul 4942  ax-pow 4993

This theorem depends on definitions:  df-bi 197  df-or 384  df-an 385  df-3an 1074  df-tru 1635  df-ex 1854  df-nf 1859  df-sb 2048  df-eu 2612  df-mo 2613  df-clab 2748  df-cleq 2754  df-clel 2757  df-nfc 2892  df-ral 3056  df-rex 3057  df-rab 3060  df-v 3343  df-dif 3719  df-un 3721  df-in 3723  df-ss 3730  df-nul 4060  df-if 4232  df-sn 4323  df-pr 4325  df-op 4329  df-uni 4590  df-br 4806  df-dm 5277  df-iota 6013  df-fv 6058

This theorem is referenced by:  elfv2ex  6392