Theorem 0map0sn0 8874

Description: The set of mappings of the empty set to the empty set is the singleton containing the empty set. (Contributed by AV, 31-Mar-2024.)

Assertion

Ref	Expression
0map0sn0	⊢ (∅ ↑m ∅) = {∅}

Proof of Theorem 0map0sn0

Step	Hyp	Ref	Expression
1		f0bi 6764	. . 3 ⊢ (𝑓:∅⟶∅ ↔ 𝑓 = ∅)
2	1	abbii 2794	. 2 ⊢ {𝑓 ∣ 𝑓:∅⟶∅} = {𝑓 ∣ 𝑓 = ∅}
3		0ex 5297	. . 3 ⊢ ∅ ∈ V
4	3, 3	mapval 8827	. 2 ⊢ (∅ ↑m ∅) = {𝑓 ∣ 𝑓:∅⟶∅}
5		df-sn 4621	. 2 ⊢ {∅} = {𝑓 ∣ 𝑓 = ∅}
6	2, 4, 5	3eqtr4i 2762	1 ⊢ (∅ ↑m ∅) = {∅}

Syntax hints:   = wceq 1533  {cab 2701  ∅c0 4314  {csn 4620  ⟶wf 6529  (class class class)co 7401   ↑_m cmap 8815

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1789  ax-4 1803  ax-5 1905  ax-6 1963  ax-7 2003  ax-8 2100  ax-9 2108  ax-10 2129  ax-11 2146  ax-12 2163  ax-ext 2695  ax-sep 5289  ax-nul 5296  ax-pow 5353  ax-pr 5417  ax-un 7718

This theorem depends on definitions:  df-bi 206  df-an 396  df-or 845  df-3an 1086  df-tru 1536  df-fal 1546  df-ex 1774  df-nf 1778  df-sb 2060  df-mo 2526  df-eu 2555  df-clab 2702  df-cleq 2716  df-clel 2802  df-nfc 2877  df-ral 3054  df-rex 3063  df-rab 3425  df-v 3468  df-sbc 3770  df-dif 3943  df-un 3945  df-in 3947  df-ss 3957  df-nul 4315  df-if 4521  df-pw 4596  df-sn 4621  df-pr 4623  df-op 4627  df-uni 4900  df-br 5139  df-opab 5201  df-id 5564  df-xp 5672  df-rel 5673  df-cnv 5674  df-co 5675  df-dm 5676  df-rn 5677  df-iota 6485  df-fun 6535  df-fn 6536  df-f 6537  df-fv 6541  df-ov 7404  df-oprab 7405  df-mpo 7406  df-map 8817

This theorem is referenced by:  efmndbas0  18803  symgvalstruct  19301  symgvalstructOLD  19302