xmetrtri - Intuitionistic Logic Explorer

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Theorem xmetrtri 13016

Description: One half of the reverse triangle inequality for the distance function of an extended metric. (Contributed by Mario Carneiro, 4-Sep-2015.)

**Assertion**
Ref	Expression
xmetrtri	$/\$ $/\$ $/\$

**Proof of Theorem xmetrtri**
Step	Hyp	Ref	Expression
1		3ancomb 976	. . 3 $/\$ $/\$ $/\$ $/\$
2		xmettri 13012	. . 3 $/\$ $/\$ $/\$
3	1, 2	sylan2b 285	. 2 $/\$ $/\$ $/\$
4		xmetcl 12992	. . . 4 $/\$ $/\$
5	4	3adant3r2 1203	. . 3 $/\$ $/\$ $/\$
6		xmetcl 12992	. . . 4 $/\$ $/\$
7	6	3adant3r1 1202	. . 3 $/\$ $/\$ $/\$
8		xmetcl 12992	. . . 4 $/\$ $/\$
9	8	3adant3r3 1204	. . 3 $/\$ $/\$ $/\$
10		xmetge0 13005	. . . 4 $/\$ $/\$
11	10	3adant3r2 1203	. . 3 $/\$ $/\$ $/\$
12		xmetge0 13005	. . . . 5 $/\$ $/\$
13	12	3adant3r1 1202	. . . 4 $/\$ $/\$ $/\$
14		ge0nemnf 9760	. . . 4 $/\$
15	7, 13, 14	syl2anc 409	. . 3 $/\$ $/\$ $/\$
16		xmetge0 13005	. . . 4 $/\$ $/\$
17	16	3adant3r3 1204	. . 3 $/\$ $/\$ $/\$
18		xlesubadd 9819	. . 3 $/\$ $/\$ $/\$ $/\$ $/\$
19	5, 7, 9, 11, 15, 17, 18	syl33anc 1243	. 2 $/\$ $/\$ $/\$
20	3, 19	mpbird 166	1 $/\$ $/\$ $/\$

Colors of variables: wff set class

Syntax hints:

wi 4 $/\$ wa 103

wb 104 $/\$ w3a 968

wcel 2136

wne 2336 class class class wbr 3982

cfv 5188 (class class class)co 5842

cc0 7753

cmnf 7931

cxr 7932

cle 7934

cxne 9705

cxad 9706

cxmet 12620

This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-ia1 105 ax-ia2 106 ax-ia3 107 ax-in1 604 ax-in2 605 ax-io 699 ax-5 1435 ax-7 1436 ax-gen 1437 ax-ie1 1481 ax-ie2 1482 ax-8 1492 ax-10 1493 ax-11 1494 ax-i12 1495 ax-bndl 1497 ax-4 1498 ax-17 1514 ax-i9 1518 ax-ial 1522 ax-i5r 1523 ax-13 2138 ax-14 2139 ax-ext 2147 ax-sep 4100 ax-pow 4153 ax-pr 4187 ax-un 4411 ax-setind 4514 ax-cnex 7844 ax-resscn 7845 ax-1cn 7846 ax-1re 7847 ax-icn 7848 ax-addcl 7849 ax-addrcl 7850 ax-mulcl 7851 ax-mulrcl 7852 ax-addcom 7853 ax-mulcom 7854 ax-addass 7855 ax-mulass 7856 ax-distr 7857 ax-i2m1 7858 ax-0lt1 7859 ax-1rid 7860 ax-0id 7861 ax-rnegex 7862 ax-precex 7863 ax-cnre 7864 ax-pre-ltirr 7865 ax-pre-ltwlin 7866 ax-pre-lttrn 7867 ax-pre-apti 7868 ax-pre-ltadd 7869 ax-pre-mulgt0 7870

This theorem depends on definitions: df-bi 116 df-dc 825 df-3or 969 df-3an 970 df-tru 1346 df-fal 1349 df-nf 1449 df-sb 1751 df-eu 2017 df-mo 2018 df-clab 2152 df-cleq 2158 df-clel 2161 df-nfc 2297 df-ne 2337 df-nel 2432 df-ral 2449 df-rex 2450 df-reu 2451 df-rab 2453 df-v 2728 df-sbc 2952 df-csb 3046 df-dif 3118 df-un 3120 df-in 3122 df-ss 3129 df-if 3521 df-pw 3561 df-sn 3582 df-pr 3583 df-op 3585 df-uni 3790 df-iun 3868 df-br 3983 df-opab 4044 df-mpt 4045 df-id 4271 df-po 4274 df-iso 4275 df-xp 4610 df-rel 4611 df-cnv 4612 df-co 4613 df-dm 4614 df-rn 4615 df-res 4616 df-ima 4617 df-iota 5153 df-fun 5190 df-fn 5191 df-f 5192 df-fv 5196 df-riota 5798 df-ov 5845 df-oprab 5846 df-mpo 5847 df-1st 6108 df-2nd 6109 df-map 6616 df-pnf 7935 df-mnf 7936 df-xr 7937 df-ltxr 7938 df-le 7939 df-sub 8071 df-neg 8072 df-2 8916 df-xneg 9708 df-xadd 9709 df-xmet 12628

This theorem is referenced by: (None)

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