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Mirrors > Home > MPE Home > Th. List > fun0 | Structured version Visualization version GIF version |
Description: The empty set is a function. Theorem 10.3 of [Quine] p. 65. (Contributed by NM, 7-Apr-1998.) |
Ref | Expression |
---|---|
fun0 | ⊢ Fun ∅ |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | 0ss 4352 | . 2 ⊢ ∅ ⊆ {〈∅, ∅〉} | |
2 | 0ex 5213 | . . 3 ⊢ ∅ ∈ V | |
3 | 2, 2 | funsn 6409 | . 2 ⊢ Fun {〈∅, ∅〉} |
4 | funss 6376 | . 2 ⊢ (∅ ⊆ {〈∅, ∅〉} → (Fun {〈∅, ∅〉} → Fun ∅)) | |
5 | 1, 3, 4 | mp2 9 | 1 ⊢ Fun ∅ |
Colors of variables: wff setvar class |
Syntax hints: ⊆ wss 3938 ∅c0 4293 {csn 4569 〈cop 4575 Fun wfun 6351 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1796 ax-4 1810 ax-5 1911 ax-6 1970 ax-7 2015 ax-8 2116 ax-9 2124 ax-10 2145 ax-11 2161 ax-12 2177 ax-ext 2795 ax-sep 5205 ax-nul 5212 ax-pr 5332 |
This theorem depends on definitions: df-bi 209 df-an 399 df-or 844 df-3an 1085 df-tru 1540 df-ex 1781 df-nf 1785 df-sb 2070 df-mo 2622 df-eu 2654 df-clab 2802 df-cleq 2816 df-clel 2895 df-nfc 2965 df-ral 3145 df-rex 3146 df-rab 3149 df-v 3498 df-dif 3941 df-un 3943 df-in 3945 df-ss 3954 df-nul 4294 df-if 4470 df-sn 4570 df-pr 4572 df-op 4576 df-br 5069 df-opab 5131 df-id 5462 df-xp 5563 df-rel 5564 df-cnv 5565 df-co 5566 df-fun 6359 |
This theorem is referenced by: funcnv0 6422 fn0 6481 0fsupp 8857 strle1 16594 lubfun 17592 glbfun 17605 1pthdlem1 27916 |
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