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Mathbox for Thierry Arnoux |
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Mirrors > Home > MPE Home > Th. List > Mathboxes > xrge0iifcv | Structured version Visualization version GIF version |
Description: The defined function's value in the real. (Contributed by Thierry Arnoux, 1-Apr-2017.) |
Ref | Expression |
---|---|
xrge0iifhmeo.1 | ⊢ 𝐹 = (𝑥 ∈ (0[,]1) ↦ if(𝑥 = 0, +∞, -(log‘𝑥))) |
Ref | Expression |
---|---|
xrge0iifcv | ⊢ (𝑋 ∈ (0(,]1) → (𝐹‘𝑋) = -(log‘𝑋)) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | iocssicc 13474 | . . . 4 ⊢ (0(,]1) ⊆ (0[,]1) | |
2 | 1 | sseli 3991 | . . 3 ⊢ (𝑋 ∈ (0(,]1) → 𝑋 ∈ (0[,]1)) |
3 | eqeq1 2739 | . . . . 5 ⊢ (𝑥 = 𝑋 → (𝑥 = 0 ↔ 𝑋 = 0)) | |
4 | fveq2 6907 | . . . . . 6 ⊢ (𝑥 = 𝑋 → (log‘𝑥) = (log‘𝑋)) | |
5 | 4 | negeqd 11500 | . . . . 5 ⊢ (𝑥 = 𝑋 → -(log‘𝑥) = -(log‘𝑋)) |
6 | 3, 5 | ifbieq2d 4557 | . . . 4 ⊢ (𝑥 = 𝑋 → if(𝑥 = 0, +∞, -(log‘𝑥)) = if(𝑋 = 0, +∞, -(log‘𝑋))) |
7 | xrge0iifhmeo.1 | . . . 4 ⊢ 𝐹 = (𝑥 ∈ (0[,]1) ↦ if(𝑥 = 0, +∞, -(log‘𝑥))) | |
8 | pnfex 11312 | . . . . 5 ⊢ +∞ ∈ V | |
9 | negex 11504 | . . . . 5 ⊢ -(log‘𝑋) ∈ V | |
10 | 8, 9 | ifex 4581 | . . . 4 ⊢ if(𝑋 = 0, +∞, -(log‘𝑋)) ∈ V |
11 | 6, 7, 10 | fvmpt 7016 | . . 3 ⊢ (𝑋 ∈ (0[,]1) → (𝐹‘𝑋) = if(𝑋 = 0, +∞, -(log‘𝑋))) |
12 | 2, 11 | syl 17 | . 2 ⊢ (𝑋 ∈ (0(,]1) → (𝐹‘𝑋) = if(𝑋 = 0, +∞, -(log‘𝑋))) |
13 | 0xr 11306 | . . . . . . 7 ⊢ 0 ∈ ℝ* | |
14 | 1re 11259 | . . . . . . 7 ⊢ 1 ∈ ℝ | |
15 | elioc2 13447 | . . . . . . 7 ⊢ ((0 ∈ ℝ* ∧ 1 ∈ ℝ) → (𝑋 ∈ (0(,]1) ↔ (𝑋 ∈ ℝ ∧ 0 < 𝑋 ∧ 𝑋 ≤ 1))) | |
16 | 13, 14, 15 | mp2an 692 | . . . . . 6 ⊢ (𝑋 ∈ (0(,]1) ↔ (𝑋 ∈ ℝ ∧ 0 < 𝑋 ∧ 𝑋 ≤ 1)) |
17 | 16 | simp2bi 1145 | . . . . 5 ⊢ (𝑋 ∈ (0(,]1) → 0 < 𝑋) |
18 | 17 | gt0ne0d 11825 | . . . 4 ⊢ (𝑋 ∈ (0(,]1) → 𝑋 ≠ 0) |
19 | 18 | neneqd 2943 | . . 3 ⊢ (𝑋 ∈ (0(,]1) → ¬ 𝑋 = 0) |
20 | 19 | iffalsed 4542 | . 2 ⊢ (𝑋 ∈ (0(,]1) → if(𝑋 = 0, +∞, -(log‘𝑋)) = -(log‘𝑋)) |
21 | 12, 20 | eqtrd 2775 | 1 ⊢ (𝑋 ∈ (0(,]1) → (𝐹‘𝑋) = -(log‘𝑋)) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ↔ wb 206 ∧ w3a 1086 = wceq 1537 ∈ wcel 2106 ifcif 4531 class class class wbr 5148 ↦ cmpt 5231 ‘cfv 6563 (class class class)co 7431 ℝcr 11152 0cc0 11153 1c1 11154 +∞cpnf 11290 ℝ*cxr 11292 < clt 11293 ≤ cle 11294 -cneg 11491 (,]cioc 13385 [,]cicc 13387 logclog 26611 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1792 ax-4 1806 ax-5 1908 ax-6 1965 ax-7 2005 ax-8 2108 ax-9 2116 ax-10 2139 ax-11 2155 ax-12 2175 ax-ext 2706 ax-sep 5302 ax-nul 5312 ax-pow 5371 ax-pr 5438 ax-un 7754 ax-cnex 11209 ax-resscn 11210 ax-1cn 11211 ax-icn 11212 ax-addcl 11213 ax-addrcl 11214 ax-mulcl 11215 ax-mulrcl 11216 ax-i2m1 11221 ax-1ne0 11222 ax-rnegex 11224 ax-rrecex 11225 ax-cnre 11226 ax-pre-lttri 11227 ax-pre-lttrn 11228 |
This theorem depends on definitions: df-bi 207 df-an 396 df-or 848 df-3or 1087 df-3an 1088 df-tru 1540 df-fal 1550 df-ex 1777 df-nf 1781 df-sb 2063 df-mo 2538 df-eu 2567 df-clab 2713 df-cleq 2727 df-clel 2814 df-nfc 2890 df-ne 2939 df-nel 3045 df-ral 3060 df-rex 3069 df-rab 3434 df-v 3480 df-sbc 3792 df-csb 3909 df-dif 3966 df-un 3968 df-in 3970 df-ss 3980 df-nul 4340 df-if 4532 df-pw 4607 df-sn 4632 df-pr 4634 df-op 4638 df-uni 4913 df-br 5149 df-opab 5211 df-mpt 5232 df-id 5583 df-po 5597 df-so 5598 df-xp 5695 df-rel 5696 df-cnv 5697 df-co 5698 df-dm 5699 df-rn 5700 df-res 5701 df-ima 5702 df-iota 6516 df-fun 6565 df-fn 6566 df-f 6567 df-f1 6568 df-fo 6569 df-f1o 6570 df-fv 6571 df-ov 7434 df-oprab 7435 df-mpo 7436 df-er 8744 df-en 8985 df-dom 8986 df-sdom 8987 df-pnf 11295 df-mnf 11296 df-xr 11297 df-ltxr 11298 df-le 11299 df-neg 11493 df-ioc 13389 df-icc 13391 |
This theorem is referenced by: xrge0iifiso 33896 xrge0iifhom 33898 |
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