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Mirrors > Home > ILE Home > Th. List > impbii | GIF version |
Description: Infer an equivalence from an implication and its converse. (Contributed by NM, 5-Aug-1993.) |
Ref | Expression |
---|---|
impbii.1 | ⊢ (𝜑 → 𝜓) |
impbii.2 | ⊢ (𝜓 → 𝜑) |
Ref | Expression |
---|---|
impbii | ⊢ (𝜑 ↔ 𝜓) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | impbii.1 | . 2 ⊢ (𝜑 → 𝜓) | |
2 | impbii.2 | . 2 ⊢ (𝜓 → 𝜑) | |
3 | bi3 112 | . 2 ⊢ ((𝜑 → 𝜓) → ((𝜓 → 𝜑) → (𝜑 ↔ 𝜓))) | |
4 | 1, 2, 3 | mp2 16 | 1 ⊢ (𝜑 ↔ 𝜓) |
Colors of variables: wff set class |
Syntax hints: → wi 4 ↔ wb 98 |
This theorem was proved from axioms: ax-1 5 ax-2 6 ax-mp 7 ax-ia2 100 ax-ia3 101 |
This theorem depends on definitions: df-bi 110 |
This theorem is referenced by: bicom 128 biid 160 2th 163 pm5.74 168 bitri 173 bibi2i 216 bi2.04 237 pm5.4 238 imdi 239 impexp 250 ancom 253 pm4.45im 317 dfbi2 368 anass 381 pm5.32 426 jcab 535 con2b 593 2false 617 pm5.21nii 620 pm4.8 623 imnan 624 notnotnot 628 orcom 647 ioran 669 oridm 674 orbi2i 679 or12 683 pm4.44 696 ordi 729 andi 731 pm4.72 736 oibabs 800 stabtestimpdc 824 pm4.82 857 rnlem 883 3jaob 1197 truanOLD 1261 xoranor 1268 falantru 1294 3impexp 1326 3impexpbicom 1327 alcom 1367 19.26 1370 19.3h 1445 19.3 1446 19.21h 1449 19.43 1519 19.9h 1534 excom 1554 19.41h 1575 19.41 1576 equcom 1593 equsalh 1614 equsex 1616 cbvalh 1636 cbvexh 1638 sbbii 1648 sbh 1659 equs45f 1683 sb6f 1684 sbcof2 1691 sbequ8 1727 sbidm 1731 sb5rf 1732 sb6rf 1733 equvin 1743 sbimv 1773 sbalyz 1875 eu2 1944 eu3h 1945 eu5 1947 mo3h 1953 euan 1956 axext4 2024 cleqh 2137 r19.26 2441 ralcom3 2477 ceqsex 2592 gencbvex 2600 gencbvex2 2601 gencbval 2602 eqvinc 2667 pm13.183 2681 rr19.3v 2682 rr19.28v 2683 reu6 2730 reu3 2731 sbnfc2 2906 difdif 3069 ddifnel 3075 ssddif 3171 difin 3174 uneqin 3188 indifdir 3193 undif3ss 3198 difrab 3211 un00 3263 undifss 3303 ssdifeq0 3305 ralidm 3321 ralf0 3324 ralm 3325 elpr2 3397 snidb 3401 difsnb 3506 preq12b 3541 preqsn 3546 axpweq 3924 sspwb 3952 unipw 3953 opm 3971 opth 3974 ssopab2b 4013 elon2 4113 unexb 4177 eusvnfb 4186 eusv2nf 4188 ralxfrALT 4199 uniexb 4205 iunpw 4211 sucelon 4229 unon 4237 sucprcreg 4273 opthreg 4280 ordsuc 4287 peano2b 4337 opelxp 4374 opthprc 4391 relop 4486 issetid 4490 elres 4646 iss 4654 issref 4707 xpmlem 4744 ssrnres 4763 dfrel2 4771 relrelss 4844 fn0 5018 funssxp 5060 f00 5081 dffo2 5110 ffoss 5158 f1o00 5161 fo00 5162 fv3 5197 dff2 5311 dffo4 5315 dffo5 5316 fmpt 5319 ffnfv 5323 fsn 5335 fsn2 5337 isores1 5454 ssoprab2b 5562 eqfnov2 5608 reldmtpos 5868 en0 6275 en1 6279 elni2 6412 ltbtwnnqq 6513 enq0ref 6531 elnp1st2nd 6574 elrealeu 6906 elreal2 6907 le2tri3i 7126 elnn0nn 8224 elnnnn0b 8226 elnnnn0c 8227 elnnz 8255 elnn0z 8258 elnnz1 8268 elz2 8312 eluz2b2 8540 elnn1uz2 8544 elioo4g 8803 eluzfz2b 8897 fzm 8902 elfz1end 8919 fzass4 8925 elfz1b 8952 nn0fz0 8978 fzolb 9009 fzom 9020 elfzo0 9038 fzo1fzo0n0 9039 elfzo0z 9040 elfzo1 9046 rexanuz 9587 rexuz3 9588 sqrt0rlem 9601 bdeq 9943 bdop 9995 bdunexb 10040 bj-2inf 10062 bj-nn0suc 10089 |
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