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Theorem dfatafv2rnb 48296
Description: The alternate function value at a class 𝐴 is defined, i.e. in the range of the function, iff the function is defined at 𝐴. (Contributed by AV, 2-Sep-2022.)
Assertion
Ref Expression
dfatafv2rnb (𝐹 defAt 𝐴 ↔ (𝐹''''𝐴) ∈ ran 𝐹)

Proof of Theorem dfatafv2rnb
StepHypRef Expression
1 funressndmafv2rn 48292 . 2 (𝐹 defAt 𝐴 → (𝐹''''𝐴) ∈ ran 𝐹)
2 ndfatafv2nrn 48290 . . . 4 (¬ 𝐹 defAt 𝐴 → (𝐹''''𝐴) ∉ ran 𝐹)
3 df-nel 3063 . . . 4 ((𝐹''''𝐴) ∉ ran 𝐹 ↔ ¬ (𝐹''''𝐴) ∈ ran 𝐹)
42, 3sylib 221 . . 3 (¬ 𝐹 defAt 𝐴 → ¬ (𝐹''''𝐴) ∈ ran 𝐹)
54con4i 115 . 2 ((𝐹''''𝐴) ∈ ran 𝐹 → 𝐹 defAt 𝐴)
61, 5impbii 212 1 (𝐹 defAt 𝐴 ↔ (𝐹''''𝐴) ∈ ran 𝐹)
Colors of variables:    wff setvar class
This proof depends on syntax axioms:  ¬ wn 3   ↔ wb 209   ∈ wcel 2145   ∉ wnel 3062  ran crn 5652   defAt wdfat 48185  ''''cafv2 48277
This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1828  ax-4 1842  ax-5 1943  ax-6 2000  ax-7 2041  ax-8 2147  ax-9 2155  ax-10 2178  ax-12 2213  ax-ext 2733  ax-sep 5249  ax-nul 5260  ax-pr 5391
This proof depends on definitions:  df-bi 210  df-an 402  df-or 862  df-3an 1105  df-tru 1573  df-fal 1583  df-ex 1813  df-nf 1817  df-sb 2100  df-mo 2565  df-eu 2595  df-clab 2740  df-cleq 2753  df-clel 2836  df-ne 2957  df-nel 3063  df-ral 3078  df-rex 3088  df-rab 3414  df-v 3453  df-dif 3902  df-un 3904  df-in 3906  df-ss 3916  df-nul 4280  df-if 4483  df-pw 4559  df-sn 4585  df-pr 4587  df-op 4591  df-uni 4868  df-br 5104  df-opab 5168  df-id 5546  df-xp 5657  df-rel 5658  df-cnv 5659  df-co 5660  df-dm 5661  df-rn 5662  df-res 5663  df-iota 6494  df-fun 6540  df-dfat 48188  df-afv2 48278
This theorem is used by:  dmafv2rnb  48298  afv2elrn  48300  tz6.12i-afv2  48312  afv2ndeffv0  48329  afv2rnfveq  48331
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