Theorem eldmrexrn 7123

Description: For any element in the domain of a function there is an element in the range of the function which is the function value for the element of the domain. (Contributed by Alexander van der Vekens, 8-Dec-2017.)

Assertion

Ref	Expression
eldmrexrn	⊢ (Fun 𝐹 → (𝑌 ∈ dom 𝐹 → ∃𝑥 ∈ ran 𝐹 𝑥 = (𝐹‘𝑌)))

Distinct variable groups:   𝑥,𝐹   𝑥,𝑌

Proof of Theorem eldmrexrn

Step	Hyp	Ref	Expression
1		fvelrn 7108	. . 3 ⊢ ((Fun 𝐹 ∧ 𝑌 ∈ dom 𝐹) → (𝐹‘𝑌) ∈ ran 𝐹)
2		eqid 2763	. . 3 ⊢ (𝐹‘𝑌) = (𝐹‘𝑌)
3		eqeq1 2767	. . . 4 ⊢ (𝑥 = (𝐹‘𝑌) → (𝑥 = (𝐹‘𝑌) ↔ (𝐹‘𝑌) = (𝐹‘𝑌)))
4	3	rspcev 3580	. . 3 ⊢ (((𝐹‘𝑌) ∈ ran 𝐹 ∧ (𝐹‘𝑌) = (𝐹‘𝑌)) → ∃𝑥 ∈ ran 𝐹 𝑥 = (𝐹‘𝑌))
5	1, 2, 4	sylancl 598	. 2 ⊢ ((Fun 𝐹 ∧ 𝑌 ∈ dom 𝐹) → ∃𝑥 ∈ ran 𝐹 𝑥 = (𝐹‘𝑌))
6	5	ex 418	1 ⊢ (Fun 𝐹 → (𝑌 ∈ dom 𝐹 → ∃𝑥 ∈ ran 𝐹 𝑥 = (𝐹‘𝑌)))

This proof depends on syntax axioms:   → wi 4   ∧ wa 401   = wceq 1570   ∈ wcel 2147  ∃wrex 3090  dom cdm 5658  ran crn 5659  Fun wfun 6560  ‘cfv 6566

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 1945  ax-6 2002  ax-7 2043  ax-8 2149  ax-9 2157  ax-10 2180  ax-12 2216  ax-ext 2735  ax-sep 5255  ax-nul 5266  ax-pr 5398

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 2102  df-mo 2567  df-eu 2597  df-clab 2742  df-cleq 2755  df-clel 2839  df-ne 2960  df-ral 3081  df-rex 3091  df-rab 3417  df-v 3456  df-ss 3901  df-dif 4050  df-in 4094  df-un 4154  df-nul 4282  df-if 4486  df-sn 4589  df-pr 4591  df-op 4841  df-uni 4873  df-br 5109  df-opab 5174  df-id 5553  df-xp 5664  df-rel 5665  df-cnv 5666  df-co 5667  df-dm 5668  df-rn 5669  df-iota 6520  df-fun 6568  df-fn 6569  df-fv 6574

This theorem is used by:  eldmrexrnb  7124