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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 5790 | . . 3 ⊢ dom ∅ = ∅ | |
2 | xpeq1 5569 | . . . . 5 ⊢ (𝐴 = ∅ → (𝐴 × 𝐴) = (∅ × 𝐴)) | |
3 | 0xp 5649 | . . . . 5 ⊢ (∅ × 𝐴) = ∅ | |
4 | 2, 3 | syl6eq 2872 | . . . 4 ⊢ (𝐴 = ∅ → (𝐴 × 𝐴) = ∅) |
5 | 4 | dmeqd 5774 | . . 3 ⊢ (𝐴 = ∅ → dom (𝐴 × 𝐴) = dom ∅) |
6 | id 22 | . . 3 ⊢ (𝐴 = ∅ → 𝐴 = ∅) | |
7 | 1, 5, 6 | 3eqtr4a 2882 | . 2 ⊢ (𝐴 = ∅ → dom (𝐴 × 𝐴) = 𝐴) |
8 | dmxp 5799 | . 2 ⊢ (𝐴 ≠ ∅ → dom (𝐴 × 𝐴) = 𝐴) | |
9 | 7, 8 | pm2.61ine 3100 | 1 ⊢ dom (𝐴 × 𝐴) = 𝐴 |
Colors of variables: wff setvar class |
Syntax hints: = wceq 1537 ∅c0 4291 × cxp 5553 dom cdm 5555 |
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 2793 ax-sep 5203 ax-nul 5210 ax-pr 5330 |
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 2800 df-cleq 2814 df-clel 2893 df-nfc 2963 df-ne 3017 df-ral 3143 df-rab 3147 df-v 3496 df-dif 3939 df-un 3941 df-in 3943 df-ss 3952 df-nul 4292 df-if 4468 df-sn 4568 df-pr 4570 df-op 4574 df-br 5067 df-opab 5129 df-xp 5561 df-dm 5565 |
This theorem is referenced by: dmxpin 5801 xpid11 5802 sofld 6044 xpider 8368 hartogslem1 9006 unxpwdom2 9052 infxpenlem 9439 fpwwe2lem13 10064 fpwwe2 10065 canth4 10069 dmrecnq 10390 homfeqbas 16966 sscfn1 17087 sscfn2 17088 ssclem 17089 isssc 17090 rescval2 17098 issubc2 17106 cofuval 17152 resfval2 17163 resf1st 17164 psssdm2 17825 tsrss 17833 decpmatval 21373 pmatcollpw3lem 21391 ustssco 22823 ustbas2 22834 psmetdmdm 22915 xmetdmdm 22945 setsmstopn 23088 tmsval 23091 tngtopn 23259 caufval 23878 grporndm 28287 dfhnorm2 28899 hhshsslem1 29044 metideq 31133 filnetlem4 33729 poimirlem3 34910 ssbnd 35081 bnd2lem 35084 ismtyval 35093 ismndo2 35167 exidreslem 35170 divrngcl 35250 isdrngo2 35251 rtrclex 39997 fnxpdmdm 44055 |
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