cxpge0 - Metamath Proof Explorer

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Theorem cxpge0 26191

Description: Nonnegative exponentiation with a real exponent is nonnegative. (Contributed by Mario Carneiro, 2-Aug-2014.)

**Assertion**
Ref	Expression
cxpge0	⊢ ((𝐴 ∈ ℝ ∧ 0 ≤ 𝐴 ∧ 𝐵 ∈ ℝ) → 0 ≤ (𝐴↑_𝑐𝐵))

**Proof of Theorem cxpge0**
Step	Hyp	Ref	Expression
1		0re 11216	. . . . . 6 ⊢ 0 ∈ ℝ
2		leloe 11300	. . . . . 6 ⊢ ((0 ∈ ℝ ∧ 𝐴 ∈ ℝ) → (0 ≤ 𝐴 ↔ (0 < 𝐴 ∨ 0 = 𝐴)))
3	1, 2	mpan 689	. . . . 5 ⊢ (𝐴 ∈ ℝ → (0 ≤ 𝐴 ↔ (0 < 𝐴 ∨ 0 = 𝐴)))
4	3	adantr 482	. . . 4 ⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) → (0 ≤ 𝐴 ↔ (0 < 𝐴 ∨ 0 = 𝐴)))
5		elrp 12976	. . . . . . 7 ⊢ (𝐴 ∈ ℝ⁺ ↔ (𝐴 ∈ ℝ ∧ 0 < 𝐴))
6		rpcxpcl 26184	. . . . . . . . 9 ⊢ ((𝐴 ∈ ℝ⁺ ∧ 𝐵 ∈ ℝ) → (𝐴↑_𝑐𝐵) ∈ ℝ⁺)
7	6	rpge0d 13020	. . . . . . . 8 ⊢ ((𝐴 ∈ ℝ⁺ ∧ 𝐵 ∈ ℝ) → 0 ≤ (𝐴↑_𝑐𝐵))
8	7	ex 414	. . . . . . 7 ⊢ (𝐴 ∈ ℝ⁺ → (𝐵 ∈ ℝ → 0 ≤ (𝐴↑_𝑐𝐵)))
9	5, 8	sylbir 234	. . . . . 6 ⊢ ((𝐴 ∈ ℝ ∧ 0 < 𝐴) → (𝐵 ∈ ℝ → 0 ≤ (𝐴↑_𝑐𝐵)))
10	9	impancom 453	. . . . 5 ⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) → (0 < 𝐴 → 0 ≤ (𝐴↑_𝑐𝐵)))
11		0le1 11737	. . . . . . . . . 10 ⊢ 0 ≤ 1
12		0cn 11206	. . . . . . . . . . 11 ⊢ 0 ∈ ℂ
13		cxp0 26178	. . . . . . . . . . 11 ⊢ (0 ∈ ℂ → (0↑_𝑐0) = 1)
14	12, 13	ax-mp 5	. . . . . . . . . 10 ⊢ (0↑_𝑐0) = 1
15	11, 14	breqtrri 5176	. . . . . . . . 9 ⊢ 0 ≤ (0↑_𝑐0)
16		simpr 486	. . . . . . . . . 10 ⊢ ((𝐵 ∈ ℝ ∧ 𝐵 = 0) → 𝐵 = 0)
17	16	oveq2d 7425	. . . . . . . . 9 ⊢ ((𝐵 ∈ ℝ ∧ 𝐵 = 0) → (0↑_𝑐𝐵) = (0↑_𝑐0))
18	15, 17	breqtrrid 5187	. . . . . . . 8 ⊢ ((𝐵 ∈ ℝ ∧ 𝐵 = 0) → 0 ≤ (0↑_𝑐𝐵))
19		0le0 12313	. . . . . . . . 9 ⊢ 0 ≤ 0
20		recn 11200	. . . . . . . . . 10 ⊢ (𝐵 ∈ ℝ → 𝐵 ∈ ℂ)
21		0cxp 26174	. . . . . . . . . 10 ⊢ ((𝐵 ∈ ℂ ∧ 𝐵 ≠ 0) → (0↑_𝑐𝐵) = 0)
22	20, 21	sylan 581	. . . . . . . . 9 ⊢ ((𝐵 ∈ ℝ ∧ 𝐵 ≠ 0) → (0↑_𝑐𝐵) = 0)
23	19, 22	breqtrrid 5187	. . . . . . . 8 ⊢ ((𝐵 ∈ ℝ ∧ 𝐵 ≠ 0) → 0 ≤ (0↑_𝑐𝐵))
24	18, 23	pm2.61dane 3030	. . . . . . 7 ⊢ (𝐵 ∈ ℝ → 0 ≤ (0↑_𝑐𝐵))
25	24	adantl 483	. . . . . 6 ⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) → 0 ≤ (0↑_𝑐𝐵))
26		oveq1 7416	. . . . . . 7 ⊢ (0 = 𝐴 → (0↑_𝑐𝐵) = (𝐴↑_𝑐𝐵))
27	26	breq2d 5161	. . . . . 6 ⊢ (0 = 𝐴 → (0 ≤ (0↑_𝑐𝐵) ↔ 0 ≤ (𝐴↑_𝑐𝐵)))
28	25, 27	syl5ibcom 244	. . . . 5 ⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) → (0 = 𝐴 → 0 ≤ (𝐴↑_𝑐𝐵)))
29	10, 28	jaod 858	. . . 4 ⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) → ((0 < 𝐴 ∨ 0 = 𝐴) → 0 ≤ (𝐴↑_𝑐𝐵)))
30	4, 29	sylbid 239	. . 3 ⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) → (0 ≤ 𝐴 → 0 ≤ (𝐴↑_𝑐𝐵)))
31	30	3impia 1118	. 2 ⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ ∧ 0 ≤ 𝐴) → 0 ≤ (𝐴↑_𝑐𝐵))
32	31	3com23 1127	1 ⊢ ((𝐴 ∈ ℝ ∧ 0 ≤ 𝐴 ∧ 𝐵 ∈ ℝ) → 0 ≤ (𝐴↑_𝑐𝐵))

Colors of variables: wff setvar class

Syntax hints: → wi 4 ↔ wb 205 ∧ wa 397 ∨ wo 846 ∧ w3a 1088 = wceq 1542 ∈ wcel 2107 ≠ wne 2941 class class class wbr 5149 (class class class)co 7409 ℂcc 11108 ℝcr 11109 0cc0 11110 1c1 11111 < clt 11248 ≤ cle 11249 ℝ⁺crp 12974 ↑_𝑐ccxp 26064

This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1798 ax-4 1812 ax-5 1914 ax-6 1972 ax-7 2012 ax-8 2109 ax-9 2117 ax-10 2138 ax-11 2155 ax-12 2172 ax-ext 2704 ax-rep 5286 ax-sep 5300 ax-nul 5307 ax-pow 5364 ax-pr 5428 ax-un 7725 ax-inf2 9636 ax-cnex 11166 ax-resscn 11167 ax-1cn 11168 ax-icn 11169 ax-addcl 11170 ax-addrcl 11171 ax-mulcl 11172 ax-mulrcl 11173 ax-mulcom 11174 ax-addass 11175 ax-mulass 11176 ax-distr 11177 ax-i2m1 11178 ax-1ne0 11179 ax-1rid 11180 ax-rnegex 11181 ax-rrecex 11182 ax-cnre 11183 ax-pre-lttri 11184 ax-pre-lttrn 11185 ax-pre-ltadd 11186 ax-pre-mulgt0 11187 ax-pre-sup 11188 ax-addf 11189 ax-mulf 11190

This theorem depends on definitions: df-bi 206 df-an 398 df-or 847 df-3or 1089 df-3an 1090 df-tru 1545 df-fal 1555 df-ex 1783 df-nf 1787 df-sb 2069 df-mo 2535 df-eu 2564 df-clab 2711 df-cleq 2725 df-clel 2811 df-nfc 2886 df-ne 2942 df-nel 3048 df-ral 3063 df-rex 3072 df-rmo 3377 df-reu 3378 df-rab 3434 df-v 3477 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-tp 4634 df-op 4636 df-uni 4910 df-int 4952 df-iun 5000 df-iin 5001 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-se 5633 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-isom 6553 df-riota 7365 df-ov 7412 df-oprab 7413 df-mpo 7414 df-of 7670 df-om 7856 df-1st 7975 df-2nd 7976 df-supp 8147 df-frecs 8266 df-wrecs 8297 df-recs 8371 df-rdg 8410 df-1o 8466 df-2o 8467 df-er 8703 df-map 8822 df-pm 8823 df-ixp 8892 df-en 8940 df-dom 8941 df-sdom 8942 df-fin 8943 df-fsupp 9362 df-fi 9406 df-sup 9437 df-inf 9438 df-oi 9505 df-card 9934 df-pnf 11250 df-mnf 11251 df-xr 11252 df-ltxr 11253 df-le 11254 df-sub 11446 df-neg 11447 df-div 11872 df-nn 12213 df-2 12275 df-3 12276 df-4 12277 df-5 12278 df-6 12279 df-7 12280 df-8 12281 df-9 12282 df-n0 12473 df-z 12559 df-dec 12678 df-uz 12823 df-q 12933 df-rp 12975 df-xneg 13092 df-xadd 13093 df-xmul 13094 df-ioo 13328 df-ioc 13329 df-ico 13330 df-icc 13331 df-fz 13485 df-fzo 13628 df-fl 13757 df-mod 13835 df-seq 13967 df-exp 14028 df-fac 14234 df-bc 14263 df-hash 14291 df-shft 15014 df-cj 15046 df-re 15047 df-im 15048 df-sqrt 15182 df-abs 15183 df-limsup 15415 df-clim 15432 df-rlim 15433 df-sum 15633 df-ef 16011 df-sin 16013 df-cos 16014 df-pi 16016 df-struct 17080 df-sets 17097 df-slot 17115 df-ndx 17127 df-base 17145 df-ress 17174 df-plusg 17210 df-mulr 17211 df-starv 17212 df-sca 17213 df-vsca 17214 df-ip 17215 df-tset 17216 df-ple 17217 df-ds 17219 df-unif 17220 df-hom 17221 df-cco 17222 df-rest 17368 df-topn 17369 df-0g 17387 df-gsum 17388 df-topgen 17389 df-pt 17390 df-prds 17393 df-xrs 17448 df-qtop 17453 df-imas 17454 df-xps 17456 df-mre 17530 df-mrc 17531 df-acs 17533 df-mgm 18561 df-sgrp 18610 df-mnd 18626 df-submnd 18672 df-mulg 18951 df-cntz 19181 df-cmn 19650 df-psmet 20936 df-xmet 20937 df-met 20938 df-bl 20939 df-mopn 20940 df-fbas 20941 df-fg 20942 df-cnfld 20945 df-top 22396 df-topon 22413 df-topsp 22435 df-bases 22449 df-cld 22523 df-ntr 22524 df-cls 22525 df-nei 22602 df-lp 22640 df-perf 22641 df-cn 22731 df-cnp 22732 df-haus 22819 df-tx 23066 df-hmeo 23259 df-fil 23350 df-fm 23442 df-flim 23443 df-flf 23444 df-xms 23826 df-ms 23827 df-tms 23828 df-cncf 24394 df-limc 25383 df-dv 25384 df-log 26065 df-cxp 26066

This theorem is referenced by: abscxp2 26201 cxple2 26205 cxpge0d 26232 cxpaddlelem 26259

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