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Mirrors > Home > MPE Home > Th. List > mgm2nsgrplem4 | Structured version Visualization version GIF version |
Description: Lemma 4 for mgm2nsgrp 18840: M is not a semigroup. (Contributed by AV, 28-Jan-2020.) (Proof shortened by AV, 31-Jan-2020.) |
Ref | Expression |
---|---|
mgm2nsgrp.s | ⊢ 𝑆 = {𝐴, 𝐵} |
mgm2nsgrp.b | ⊢ (Base‘𝑀) = 𝑆 |
mgm2nsgrp.o | ⊢ (+g‘𝑀) = (𝑥 ∈ 𝑆, 𝑦 ∈ 𝑆 ↦ if((𝑥 = 𝐴 ∧ 𝑦 = 𝐴), 𝐵, 𝐴)) |
Ref | Expression |
---|---|
mgm2nsgrplem4 | ⊢ ((♯‘𝑆) = 2 → 𝑀 ∉ Smgrp) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | mgm2nsgrp.s | . . . 4 ⊢ 𝑆 = {𝐴, 𝐵} | |
2 | 1 | hashprdifel 14363 | . . 3 ⊢ ((♯‘𝑆) = 2 → (𝐴 ∈ 𝑆 ∧ 𝐵 ∈ 𝑆 ∧ 𝐴 ≠ 𝐵)) |
3 | simp1 1135 | . . . 4 ⊢ ((𝐴 ∈ 𝑆 ∧ 𝐵 ∈ 𝑆 ∧ 𝐴 ≠ 𝐵) → 𝐴 ∈ 𝑆) | |
4 | simp2 1136 | . . . 4 ⊢ ((𝐴 ∈ 𝑆 ∧ 𝐵 ∈ 𝑆 ∧ 𝐴 ≠ 𝐵) → 𝐵 ∈ 𝑆) | |
5 | 3, 3, 4 | 3jca 1127 | . . 3 ⊢ ((𝐴 ∈ 𝑆 ∧ 𝐵 ∈ 𝑆 ∧ 𝐴 ≠ 𝐵) → (𝐴 ∈ 𝑆 ∧ 𝐴 ∈ 𝑆 ∧ 𝐵 ∈ 𝑆)) |
6 | 2, 5 | syl 17 | . 2 ⊢ ((♯‘𝑆) = 2 → (𝐴 ∈ 𝑆 ∧ 𝐴 ∈ 𝑆 ∧ 𝐵 ∈ 𝑆)) |
7 | simp3 1137 | . . . 4 ⊢ ((𝐴 ∈ 𝑆 ∧ 𝐵 ∈ 𝑆 ∧ 𝐴 ≠ 𝐵) → 𝐴 ≠ 𝐵) | |
8 | mgm2nsgrp.b | . . . . . 6 ⊢ (Base‘𝑀) = 𝑆 | |
9 | mgm2nsgrp.o | . . . . . 6 ⊢ (+g‘𝑀) = (𝑥 ∈ 𝑆, 𝑦 ∈ 𝑆 ↦ if((𝑥 = 𝐴 ∧ 𝑦 = 𝐴), 𝐵, 𝐴)) | |
10 | eqid 2731 | . . . . . 6 ⊢ (+g‘𝑀) = (+g‘𝑀) | |
11 | 1, 8, 9, 10 | mgm2nsgrplem2 18837 | . . . . 5 ⊢ ((𝐴 ∈ 𝑆 ∧ 𝐵 ∈ 𝑆) → ((𝐴(+g‘𝑀)𝐴)(+g‘𝑀)𝐵) = 𝐴) |
12 | 11 | 3adant3 1131 | . . . 4 ⊢ ((𝐴 ∈ 𝑆 ∧ 𝐵 ∈ 𝑆 ∧ 𝐴 ≠ 𝐵) → ((𝐴(+g‘𝑀)𝐴)(+g‘𝑀)𝐵) = 𝐴) |
13 | 1, 8, 9, 10 | mgm2nsgrplem3 18838 | . . . . 5 ⊢ ((𝐴 ∈ 𝑆 ∧ 𝐵 ∈ 𝑆) → (𝐴(+g‘𝑀)(𝐴(+g‘𝑀)𝐵)) = 𝐵) |
14 | 13 | 3adant3 1131 | . . . 4 ⊢ ((𝐴 ∈ 𝑆 ∧ 𝐵 ∈ 𝑆 ∧ 𝐴 ≠ 𝐵) → (𝐴(+g‘𝑀)(𝐴(+g‘𝑀)𝐵)) = 𝐵) |
15 | 7, 12, 14 | 3netr4d 3017 | . . 3 ⊢ ((𝐴 ∈ 𝑆 ∧ 𝐵 ∈ 𝑆 ∧ 𝐴 ≠ 𝐵) → ((𝐴(+g‘𝑀)𝐴)(+g‘𝑀)𝐵) ≠ (𝐴(+g‘𝑀)(𝐴(+g‘𝑀)𝐵))) |
16 | 2, 15 | syl 17 | . 2 ⊢ ((♯‘𝑆) = 2 → ((𝐴(+g‘𝑀)𝐴)(+g‘𝑀)𝐵) ≠ (𝐴(+g‘𝑀)(𝐴(+g‘𝑀)𝐵))) |
17 | 8 | eqcomi 2740 | . . 3 ⊢ 𝑆 = (Base‘𝑀) |
18 | 17, 10 | isnsgrp 18649 | . 2 ⊢ ((𝐴 ∈ 𝑆 ∧ 𝐴 ∈ 𝑆 ∧ 𝐵 ∈ 𝑆) → (((𝐴(+g‘𝑀)𝐴)(+g‘𝑀)𝐵) ≠ (𝐴(+g‘𝑀)(𝐴(+g‘𝑀)𝐵)) → 𝑀 ∉ Smgrp)) |
19 | 6, 16, 18 | sylc 65 | 1 ⊢ ((♯‘𝑆) = 2 → 𝑀 ∉ Smgrp) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ∧ wa 395 ∧ w3a 1086 = wceq 1540 ∈ wcel 2105 ≠ wne 2939 ∉ wnel 3045 ifcif 4529 {cpr 4631 ‘cfv 6544 (class class class)co 7412 ∈ cmpo 7414 2c2 12272 ♯chash 14295 Basecbs 17149 +gcplusg 17202 Smgrpcsgrp 18644 |
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 1912 ax-6 1970 ax-7 2010 ax-8 2107 ax-9 2115 ax-10 2136 ax-11 2153 ax-12 2170 ax-ext 2702 ax-sep 5300 ax-nul 5307 ax-pow 5364 ax-pr 5428 ax-un 7728 ax-cnex 11169 ax-resscn 11170 ax-1cn 11171 ax-icn 11172 ax-addcl 11173 ax-addrcl 11174 ax-mulcl 11175 ax-mulrcl 11176 ax-mulcom 11177 ax-addass 11178 ax-mulass 11179 ax-distr 11180 ax-i2m1 11181 ax-1ne0 11182 ax-1rid 11183 ax-rnegex 11184 ax-rrecex 11185 ax-cnre 11186 ax-pre-lttri 11187 ax-pre-lttrn 11188 ax-pre-ltadd 11189 ax-pre-mulgt0 11190 |
This theorem depends on definitions: df-bi 206 df-an 396 df-or 845 df-3or 1087 df-3an 1088 df-tru 1543 df-fal 1553 df-ex 1781 df-nf 1785 df-sb 2067 df-mo 2533 df-eu 2562 df-clab 2709 df-cleq 2723 df-clel 2809 df-nfc 2884 df-ne 2940 df-nel 3046 df-ral 3061 df-rex 3070 df-reu 3376 df-rab 3432 df-v 3475 df-sbc 3779 df-csb 3895 df-dif 3952 df-un 3954 df-in 3956 df-ss 3966 df-pss 3968 df-nul 4324 df-if 4530 df-pw 4605 df-sn 4630 df-pr 4632 df-op 4636 df-uni 4910 df-int 4952 df-iun 5000 df-br 5150 df-opab 5212 df-mpt 5233 df-tr 5267 df-id 5575 df-eprel 5581 df-po 5589 df-so 5590 df-fr 5632 df-we 5634 df-xp 5683 df-rel 5684 df-cnv 5685 df-co 5686 df-dm 5687 df-rn 5688 df-res 5689 df-ima 5690 df-pred 6301 df-ord 6368 df-on 6369 df-lim 6370 df-suc 6371 df-iota 6496 df-fun 6546 df-fn 6547 df-f 6548 df-f1 6549 df-fo 6550 df-f1o 6551 df-fv 6552 df-riota 7368 df-ov 7415 df-oprab 7416 df-mpo 7417 df-om 7859 df-1st 7978 df-2nd 7979 df-frecs 8269 df-wrecs 8300 df-recs 8374 df-rdg 8413 df-1o 8469 df-oadd 8473 df-er 8706 df-en 8943 df-dom 8944 df-sdom 8945 df-fin 8946 df-dju 9899 df-card 9937 df-pnf 11255 df-mnf 11256 df-xr 11257 df-ltxr 11258 df-le 11259 df-sub 11451 df-neg 11452 df-nn 12218 df-2 12280 df-n0 12478 df-z 12564 df-uz 12828 df-fz 13490 df-hash 14296 df-sgrp 18645 |
This theorem is referenced by: mgm2nsgrp 18840 mgmnsgrpex 18849 |
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