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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 117 | . 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 103 |
This theorem was proved from axioms: ax-1 5 ax-2 6 ax-mp 7 ax-ia2 105 ax-ia3 106 |
This theorem depends on definitions: df-bi 115 |
This theorem is referenced by: bicom 138 biid 169 2th 172 pm5.74 177 bitri 182 bibi2i 225 bi2.04 246 pm5.4 247 imdi 248 impexp 259 ancom 262 pm4.45im 327 dfbi2 380 anass 393 pm5.32 440 jcab 567 con2b 625 2false 649 pm5.21nii 652 pm4.8 655 imnan 656 notnotnot 660 orcom 679 ioran 701 oridm 706 orbi2i 711 or12 715 pm4.44 728 ordi 762 andi 764 pm4.72 769 oibabs 833 stabtestimpdc 857 pm4.82 891 rnlem 917 3jaob 1233 xoranor 1308 falantru 1334 3impexp 1366 3impexpbicom 1367 alcom 1407 19.26 1410 19.3h 1485 19.3 1486 19.21h 1489 19.43 1559 19.9h 1574 excom 1594 19.41h 1615 19.41 1616 equcom 1633 equsalh 1654 equsex 1656 cbvalh 1676 cbvexh 1678 sbbii 1688 sbh 1699 equs45f 1723 sb6f 1724 sbcof2 1731 sbequ8 1768 sbidm 1772 sb5rf 1773 sb6rf 1774 equvin 1784 sbimv 1814 sbalyz 1916 eu2 1985 eu3h 1986 eu5 1988 mo3h 1994 euan 1997 axext4 2065 cleqh 2178 r19.26 2485 ralcom3 2521 ceqsex 2637 gencbvex 2645 gencbvex2 2646 gencbval 2647 eqvinc 2718 pm13.183 2732 rr19.3v 2733 rr19.28v 2734 reu6 2781 reu3 2782 sbnfc2 2962 difdif 3097 ddifnel 3103 ddifstab 3104 ssddif 3198 difin 3201 uneqin 3215 indifdir 3220 undif3ss 3225 difrab 3238 un00 3290 undifss 3323 ssdifeq0 3325 ralidm 3341 ralf0 3344 ralm 3345 elpr2 3420 snidb 3424 difsnb 3528 preq12b 3562 preqsn 3567 axpweq 3945 sspwb 3971 unipw 3972 opm 3989 opth 3992 ssopab2b 4031 elon2 4131 unexb 4195 eusvnfb 4204 eusv2nf 4206 ralxfrALT 4217 uniexb 4223 iunpw 4229 sucelon 4247 unon 4255 sucprcreg 4292 opthreg 4299 ordsuc 4306 peano2b 4355 opelxp 4392 opthprc 4409 relop 4504 issetid 4508 elres 4664 iss 4674 issref 4727 xpmlem 4764 ssrnres 4783 dfrel2 4791 relrelss 4864 fn0 5038 funssxp 5080 f00 5101 dffo2 5130 ffoss 5178 f1o00 5181 fo00 5182 fv3 5218 dff2 5332 dffo4 5336 dffo5 5337 fmpt 5340 ffnfv 5344 fsn 5356 fsn2 5358 isores1 5474 ssoprab2b 5582 eqfnov2 5628 cnvoprab 5875 reldmtpos 5891 en0 6298 en1 6302 elni2 6504 ltbtwnnqq 6605 enq0ref 6623 elnp1st2nd 6666 elrealeu 6998 elreal2 6999 le2tri3i 7219 elnn0nn 8330 elnnnn0b 8332 elnnnn0c 8333 elnnz 8361 elnn0z 8364 elnnz1 8374 elz2 8419 eluz2b2 8690 elnn1uz2 8694 elioo4g 8957 eluzfz2b 9052 fzm 9057 elfz1end 9074 fzass4 9080 elfz1b 9107 nn0fz0 9133 fzolb 9162 fzom 9173 elfzo0 9191 fzo1fzo0n0 9192 elfzo0z 9193 elfzo1 9199 rexanuz 9874 rexuz3 9876 sqrt0rlem 9889 fz01or 10278 infssuzex 10345 isprm6 10526 oddpwdclemdc 10551 bdeq 10614 bdop 10666 bdunexb 10711 bj-2inf 10733 bj-nn0suc 10759 |
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