Theorem dmsnop 6236

Description: The domain of a singleton of an ordered pair is the singleton of the first member. (Contributed by NM, 30-Jan-2004.) (Proof shortened by Andrew Salmon, 27-Aug-2011.) (Revised by Mario Carneiro, 26-Apr-2015.)

Hypothesis

Ref	Expression
dmsnop.1	⊢ 𝐵 ∈ V

Assertion

Ref	Expression
dmsnop	⊢ dom {⟨𝐴, 𝐵⟩} = {𝐴}

Proof of Theorem dmsnop

Step	Hyp	Ref	Expression
1		dmsnop.1	. 2 ⊢ 𝐵 ∈ V
2		dmsnopg 6233	. 2 ⊢ (𝐵 ∈ V → dom {⟨𝐴, 𝐵⟩} = {𝐴})
3	1, 2	ax-mp 5	1 ⊢ dom {⟨𝐴, 𝐵⟩} = {𝐴}

This proof depends on syntax axioms:   = wceq 1570   ∈ wcel 2147  Vcvv 3454  {csn 4588  ⟨cop 4840  dom cdm 5658

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-ext 2735  ax-sep 5255  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-sb 2102  df-clab 2742  df-cleq 2755  df-clel 2839  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-br 5109  df-dm 5668

This theorem is used by:  dmtpop  6238  dmsnsnsn  6240  op1sta  6245  snres0  6327  funtp  6627  funopdmsn  7186  frrlem14  8355  tfrlem10  8433  ac6sfi  9313  dcomex  10564  axdc3lem4  10570  cnfldfunALT  21745  noextend  28080  nosupbday  28119  nosupbnd1  28128  nosupbnd2  28130  noinfbday  28134  noinfbnd1  28143  noinfbnd2  28145  bnj1416  35780  bnj1421  35783  fineqvac  35925  subfacp1lem2a  36153  subfacp1lem5  36157