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Mirrors > Home > MPE Home > Th. List > dmxpid | Structured version Visualization version GIF version |
Description: The domain of a Cartesian square. (Contributed by NM, 28-Jul-1995.) |
Ref | Expression |
---|---|
dmxpid | ⊢ dom (𝐴 × 𝐴) = 𝐴 |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | dm0 5774 | . . 3 ⊢ dom ∅ = ∅ | |
2 | xpeq1 5550 | . . . . 5 ⊢ (𝐴 = ∅ → (𝐴 × 𝐴) = (∅ × 𝐴)) | |
3 | 0xp 5631 | . . . . 5 ⊢ (∅ × 𝐴) = ∅ | |
4 | 2, 3 | eqtrdi 2787 | . . . 4 ⊢ (𝐴 = ∅ → (𝐴 × 𝐴) = ∅) |
5 | 4 | dmeqd 5759 | . . 3 ⊢ (𝐴 = ∅ → dom (𝐴 × 𝐴) = dom ∅) |
6 | id 22 | . . 3 ⊢ (𝐴 = ∅ → 𝐴 = ∅) | |
7 | 1, 5, 6 | 3eqtr4a 2797 | . 2 ⊢ (𝐴 = ∅ → dom (𝐴 × 𝐴) = 𝐴) |
8 | dmxp 5783 | . 2 ⊢ (𝐴 ≠ ∅ → dom (𝐴 × 𝐴) = 𝐴) | |
9 | 7, 8 | pm2.61ine 3015 | 1 ⊢ dom (𝐴 × 𝐴) = 𝐴 |
Colors of variables: wff setvar class |
Syntax hints: = wceq 1543 ∅c0 4223 × cxp 5534 dom cdm 5536 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1803 ax-4 1817 ax-5 1918 ax-6 1976 ax-7 2018 ax-8 2114 ax-9 2122 ax-10 2143 ax-11 2160 ax-12 2177 ax-ext 2708 ax-sep 5177 ax-nul 5184 ax-pr 5307 |
This theorem depends on definitions: df-bi 210 df-an 400 df-or 848 df-3an 1091 df-tru 1546 df-fal 1556 df-ex 1788 df-nf 1792 df-sb 2073 df-mo 2539 df-eu 2568 df-clab 2715 df-cleq 2728 df-clel 2809 df-nfc 2879 df-ne 2933 df-ral 3056 df-rab 3060 df-v 3400 df-dif 3856 df-un 3858 df-in 3860 df-ss 3870 df-nul 4224 df-if 4426 df-sn 4528 df-pr 4530 df-op 4534 df-br 5040 df-opab 5102 df-xp 5542 df-dm 5546 |
This theorem is referenced by: dmxpin 5785 xpid11 5786 sofld 6030 xpider 8448 hartogslem1 9136 unxpwdom2 9182 infxpenlem 9592 fpwwe2lem12 10221 fpwwe2 10222 canth4 10226 dmrecnq 10547 homfeqbas 17153 sscfn1 17276 sscfn2 17277 ssclem 17278 isssc 17279 rescval2 17287 issubc2 17296 cofuval 17342 resfval2 17353 resf1st 17354 psssdm2 18041 tsrss 18049 decpmatval 21616 pmatcollpw3lem 21634 ustssco 23066 ustbas2 23077 psmetdmdm 23157 xmetdmdm 23187 setsmstopn 23330 tmsval 23333 tngtopn 23502 caufval 24126 grporndm 28545 dfhnorm2 29157 hhshsslem1 29302 metideq 31511 filnetlem4 34256 poimirlem3 35466 ssbnd 35632 bnd2lem 35635 ismtyval 35644 ismndo2 35718 exidreslem 35721 divrngcl 35801 isdrngo2 35802 rtrclex 40842 fnxpdmdm 44938 |
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