Metamath Proof Explorer


Theorem lhop2

Description: L'Hôpital's Rule for limits from the left. If F and G are differentiable real functions on ( A , B ) , and F and G both approach 0 at B , and G ( x ) and G ' ( x ) are not zero on ( A , B ) , and the limit of F ' ( x ) / G ' ( x ) at B is C , then the limit F ( x ) / G ( x ) at B also exists and equals C . (Contributed by Mario Carneiro, 29-Dec-2016)

Ref Expression
Hypotheses lhop2.a φA*
lhop2.b φB
lhop2.l φA<B
lhop2.f φF:AB
lhop2.g φG:AB
lhop2.if φdomF=AB
lhop2.ig φdomG=AB
lhop2.f0 φ0FlimB
lhop2.g0 φ0GlimB
lhop2.gn0 φ¬0ranG
lhop2.gd0 φ¬0ranG
lhop2.c φCzABFzGzlimB
Assertion lhop2 φCzABFzGzlimB

Proof

Step Hyp Ref Expression
1 lhop2.a φA*
2 lhop2.b φB
3 lhop2.l φA<B
4 lhop2.f φF:AB
5 lhop2.g φG:AB
6 lhop2.if φdomF=AB
7 lhop2.ig φdomG=AB
8 lhop2.f0 φ0FlimB
9 lhop2.g0 φ0GlimB
10 lhop2.gn0 φ¬0ranG
11 lhop2.gd0 φ¬0ranG
12 lhop2.c φCzABFzGzlimB
13 qssre
14 2 rexrd φB*
15 qbtwnxr A*B*A<BaA<aa<B
16 1 14 3 15 syl3anc φaA<aa<B
17 ssrexv aA<aa<BaA<aa<B
18 13 16 17 mpsyl φaA<aa<B
19 simpr φaA<aa<BzaBzaB
20 simprl φaA<aa<Ba
21 20 adantr φaA<aa<BzaBa
22 2 ad2antrr φaA<aa<BzaBB
23 elioore zaBz
24 23 adantl φaA<aa<BzaBz
25 iooneg aBzzaBzBa
26 21 22 24 25 syl3anc φaA<aa<BzaBzaBzBa
27 19 26 mpbid φaA<aa<BzaBzBa
28 27 adantrr φaA<aa<BzaBzBzBa
29 4 ad2antrr φaA<aa<BxBaF:AB
30 elioore xBax
31 30 adantl φaA<aa<BxBax
32 31 recnd φaA<aa<BxBax
33 32 negnegd φaA<aa<BxBax=x
34 simpr φaA<aa<BxBaxBa
35 33 34 eqeltrd φaA<aa<BxBaxBa
36 20 adantr φaA<aa<BxBaa
37 2 ad2antrr φaA<aa<BxBaB
38 31 renegcld φaA<aa<BxBax
39 iooneg aBxxaBxBa
40 36 37 38 39 syl3anc φaA<aa<BxBaxaBxBa
41 35 40 mpbird φaA<aa<BxBaxaB
42 1 adantr φaA<aa<BA*
43 20 rexrd φaA<aa<Ba*
44 simprrl φaA<aa<BA<a
45 42 43 44 xrltled φaA<aa<BAa
46 iooss1 A*AaaBAB
47 42 45 46 syl2anc φaA<aa<BaBAB
48 47 sselda φaA<aa<BxaBxAB
49 41 48 syldan φaA<aa<BxBaxAB
50 29 49 ffvelcdmd φaA<aa<BxBaFx
51 50 recnd φaA<aa<BxBaFx
52 5 ad2antrr φaA<aa<BxBaG:AB
53 52 49 ffvelcdmd φaA<aa<BxBaGx
54 53 recnd φaA<aa<BxBaGx
55 10 ad2antrr φaA<aa<BxBa¬0ranG
56 5 adantr φaA<aa<BG:AB
57 ax-resscn
58 fss G:ABG:AB
59 56 57 58 sylancl φaA<aa<BG:AB
60 59 adantr φaA<aa<BxBaG:AB
61 60 ffnd φaA<aa<BxBaGFnAB
62 fnfvelrn GFnABxABGxranG
63 61 49 62 syl2anc φaA<aa<BxBaGxranG
64 eleq1 Gx=0GxranG0ranG
65 63 64 syl5ibcom φaA<aa<BxBaGx=00ranG
66 65 necon3bd φaA<aa<BxBa¬0ranGGx0
67 55 66 mpd φaA<aa<BxBaGx0
68 51 54 67 divcld φaA<aa<BxBaFxGx
69 limcresi zzlimBzzaBlimB
70 ioossre aB
71 resmpt aBzzaB=zaBz
72 70 71 ax-mp zzaB=zaBz
73 72 oveq1i zzaBlimB=zaBzlimB
74 69 73 sseqtri zzlimBzaBzlimB
75 eqid zz=zz
76 75 negcncf zz:cn
77 57 76 mp1i φaA<aa<Bzz:cn
78 2 adantr φaA<aa<BB
79 negeq z=Bz=B
80 77 78 79 cnmptlimc φaA<aa<BBzzlimB
81 74 80 sselid φaA<aa<BBzaBzlimB
82 78 renegcld φaA<aa<BB
83 20 renegcld φaA<aa<Ba
84 83 rexrd φaA<aa<Ba*
85 simprrr φaA<aa<Ba<B
86 20 78 ltnegd φaA<aa<Ba<BB<a
87 85 86 mpbid φaA<aa<BB<a
88 50 fmpttd φaA<aa<BxBaFx:Ba
89 53 fmpttd φaA<aa<BxBaGx:Ba
90 reelprrecn
91 90 a1i φaA<aa<B
92 neg1cn 1
93 92 a1i φaA<aa<BxBa1
94 4 adantr φaA<aa<BF:AB
95 94 ffvelcdmda φaA<aa<ByABFy
96 95 recnd φaA<aa<ByABFy
97 fvexd φaA<aa<ByABFyV
98 1cnd φaA<aa<BxBa1
99 simpr φaA<aa<Bxx
100 99 recnd φaA<aa<Bxx
101 1cnd φaA<aa<Bx1
102 91 dvmptid φaA<aa<Bdxxdx=x1
103 ioossre Ba
104 103 a1i φaA<aa<BBa
105 eqid TopOpenfld=TopOpenfld
106 105 tgioo2 topGenran.=TopOpenfld𝑡
107 iooretop BatopGenran.
108 107 a1i φaA<aa<BBatopGenran.
109 91 100 101 102 104 106 105 108 dvmptres φaA<aa<BdxBaxdx=xBa1
110 91 32 98 109 dvmptneg φaA<aa<BdxBaxdx=xBa1
111 94 feqmptd φaA<aa<BF=yABFy
112 111 oveq2d φaA<aa<BDF=dyABFydy
113 dvf F:domF
114 6 adantr φaA<aa<BdomF=AB
115 114 feq2d φaA<aa<BF:domFF:AB
116 113 115 mpbii φaA<aa<BF:AB
117 116 feqmptd φaA<aa<BDF=yABFy
118 112 117 eqtr3d φaA<aa<BdyABFydy=yABFy
119 fveq2 y=xFy=Fx
120 fveq2 y=xFy=Fx
121 91 91 49 93 96 97 110 118 119 120 dvmptco φaA<aa<BdxBaFxdx=xBaFx-1
122 116 adantr φaA<aa<BxBaF:AB
123 122 49 ffvelcdmd φaA<aa<BxBaFx
124 123 93 mulcomd φaA<aa<BxBaFx-1=-1Fx
125 123 mulm1d φaA<aa<BxBa-1Fx=Fx
126 124 125 eqtrd φaA<aa<BxBaFx-1=Fx
127 126 mpteq2dva φaA<aa<BxBaFx-1=xBaFx
128 121 127 eqtrd φaA<aa<BdxBaFxdx=xBaFx
129 128 dmeqd φaA<aa<BdomdxBaFxdx=domxBaFx
130 negex FxV
131 eqid xBaFx=xBaFx
132 130 131 dmmpti domxBaFx=Ba
133 129 132 eqtrdi φaA<aa<BdomdxBaFxdx=Ba
134 56 ffvelcdmda φaA<aa<ByABGy
135 134 recnd φaA<aa<ByABGy
136 fvexd φaA<aa<ByABGyV
137 56 feqmptd φaA<aa<BG=yABGy
138 137 oveq2d φaA<aa<BDG=dyABGydy
139 dvf G:domG
140 7 adantr φaA<aa<BdomG=AB
141 140 feq2d φaA<aa<BG:domGG:AB
142 139 141 mpbii φaA<aa<BG:AB
143 142 feqmptd φaA<aa<BDG=yABGy
144 138 143 eqtr3d φaA<aa<BdyABGydy=yABGy
145 fveq2 y=xGy=Gx
146 fveq2 y=xGy=Gx
147 91 91 49 93 135 136 110 144 145 146 dvmptco φaA<aa<BdxBaGxdx=xBaGx-1
148 142 adantr φaA<aa<BxBaG:AB
149 148 49 ffvelcdmd φaA<aa<BxBaGx
150 149 93 mulcomd φaA<aa<BxBaGx-1=-1Gx
151 149 mulm1d φaA<aa<BxBa-1Gx=Gx
152 150 151 eqtrd φaA<aa<BxBaGx-1=Gx
153 152 mpteq2dva φaA<aa<BxBaGx-1=xBaGx
154 147 153 eqtrd φaA<aa<BdxBaGxdx=xBaGx
155 154 dmeqd φaA<aa<BdomdxBaGxdx=domxBaGx
156 negex GxV
157 eqid xBaGx=xBaGx
158 156 157 dmmpti domxBaGx=Ba
159 155 158 eqtrdi φaA<aa<BdomdxBaGxdx=Ba
160 49 adantrr φaA<aa<BxBaxBxAB
161 limcresi xxlimBxxBalimB
162 resmpt BaxxBa=xBax
163 103 162 ax-mp xxBa=xBax
164 163 oveq1i xxBalimB=xBaxlimB
165 161 164 sseqtri xxlimBxBaxlimB
166 78 recnd φaA<aa<BB
167 166 negnegd φaA<aa<BB=B
168 eqid xx=xx
169 168 negcncf xx:cn
170 57 169 mp1i φaA<aa<Bxx:cn
171 negeq x=Bx=B
172 170 82 171 cnmptlimc φaA<aa<BBxxlimB
173 167 172 eqeltrrd φaA<aa<BBxxlimB
174 165 173 sselid φaA<aa<BBxBaxlimB
175 8 adantr φaA<aa<B0FlimB
176 111 oveq1d φaA<aa<BFlimB=yABFylimB
177 175 176 eleqtrd φaA<aa<B0yABFylimB
178 eliooord xBaB<xx<a
179 178 adantl φaA<aa<BxBaB<xx<a
180 179 simpld φaA<aa<BxBaB<x
181 37 31 180 ltnegcon1d φaA<aa<BxBax<B
182 38 181 ltned φaA<aa<BxBaxB
183 182 neneqd φaA<aa<BxBa¬x=B
184 183 pm2.21d φaA<aa<BxBax=BFx=0
185 184 impr φaA<aa<BxBax=BFx=0
186 160 96 174 177 119 185 limcco φaA<aa<B0xBaFxlimB
187 9 adantr φaA<aa<B0GlimB
188 137 oveq1d φaA<aa<BGlimB=yABGylimB
189 187 188 eleqtrd φaA<aa<B0yABGylimB
190 183 pm2.21d φaA<aa<BxBax=BGx=0
191 190 impr φaA<aa<BxBax=BGx=0
192 160 135 174 189 145 191 limcco φaA<aa<B0xBaGxlimB
193 63 fmpttd φaA<aa<BxBaGx:BaranG
194 193 frnd φaA<aa<BranxBaGxranG
195 10 adantr φaA<aa<B¬0ranG
196 194 195 ssneldd φaA<aa<B¬0ranxBaGx
197 11 adantr φaA<aa<B¬0ranG
198 154 rneqd φaA<aa<BrandxBaGxdx=ranxBaGx
199 198 eleq2d φaA<aa<B0randxBaGxdx0ranxBaGx
200 157 156 elrnmpti 0ranxBaGxxBa0=Gx
201 eqcom 0=GxGx=0
202 149 negeq0d φaA<aa<BxBaGx=0Gx=0
203 148 ffnd φaA<aa<BxBaGFnAB
204 fnfvelrn GFnABxABGxranG
205 203 49 204 syl2anc φaA<aa<BxBaGxranG
206 eleq1 Gx=0GxranG0ranG
207 205 206 syl5ibcom φaA<aa<BxBaGx=00ranG
208 202 207 sylbird φaA<aa<BxBaGx=00ranG
209 201 208 biimtrid φaA<aa<BxBa0=Gx0ranG
210 209 rexlimdva φaA<aa<BxBa0=Gx0ranG
211 200 210 biimtrid φaA<aa<B0ranxBaGx0ranG
212 199 211 sylbid φaA<aa<B0randxBaGxdx0ranG
213 197 212 mtod φaA<aa<B¬0randxBaGxdx
214 116 ffvelcdmda φaA<aa<BzABFz
215 142 ffvelcdmda φaA<aa<BzABGz
216 11 ad2antrr φaA<aa<BzAB¬0ranG
217 142 ffnd φaA<aa<BGFnAB
218 fnfvelrn GFnABzABGzranG
219 217 218 sylan φaA<aa<BzABGzranG
220 eleq1 Gz=0GzranG0ranG
221 219 220 syl5ibcom φaA<aa<BzABGz=00ranG
222 221 necon3bd φaA<aa<BzAB¬0ranGGz0
223 216 222 mpd φaA<aa<BzABGz0
224 214 215 223 divcld φaA<aa<BzABFzGz
225 12 adantr φaA<aa<BCzABFzGzlimB
226 fveq2 z=xFz=Fx
227 fveq2 z=xGz=Gx
228 226 227 oveq12d z=xFzGz=FxGx
229 183 pm2.21d φaA<aa<BxBax=BFxGx=C
230 229 impr φaA<aa<BxBax=BFxGx=C
231 160 224 174 225 228 230 limcco φaA<aa<BCxBaFxGxlimB
232 nfcv _x
233 nfcv _xD
234 nfmpt1 _xxBaFx
235 232 233 234 nfov _xdxBaFxdx
236 nfcv _xy
237 235 236 nffv _xdxBaFxdxy
238 nfcv _x÷
239 nfmpt1 _xxBaGx
240 232 233 239 nfov _xdxBaGxdx
241 240 236 nffv _xdxBaGxdxy
242 237 238 241 nfov _xdxBaFxdxydxBaGxdxy
243 nfcv _ydxBaFxdxxdxBaGxdxx
244 fveq2 y=xdxBaFxdxy=dxBaFxdxx
245 fveq2 y=xdxBaGxdxy=dxBaGxdxx
246 244 245 oveq12d y=xdxBaFxdxydxBaGxdxy=dxBaFxdxxdxBaGxdxx
247 242 243 246 cbvmpt yBadxBaFxdxydxBaGxdxy=xBadxBaFxdxxdxBaGxdxx
248 128 fveq1d φaA<aa<BdxBaFxdxx=xBaFxx
249 131 fvmpt2 xBaFxVxBaFxx=Fx
250 130 249 mpan2 xBaxBaFxx=Fx
251 248 250 sylan9eq φaA<aa<BxBadxBaFxdxx=Fx
252 154 fveq1d φaA<aa<BdxBaGxdxx=xBaGxx
253 157 fvmpt2 xBaGxVxBaGxx=Gx
254 156 253 mpan2 xBaxBaGxx=Gx
255 252 254 sylan9eq φaA<aa<BxBadxBaGxdxx=Gx
256 251 255 oveq12d φaA<aa<BxBadxBaFxdxxdxBaGxdxx=FxGx
257 11 ad2antrr φaA<aa<BxBa¬0ranG
258 207 necon3bd φaA<aa<BxBa¬0ranGGx0
259 257 258 mpd φaA<aa<BxBaGx0
260 123 149 259 div2negd φaA<aa<BxBaFxGx=FxGx
261 256 260 eqtrd φaA<aa<BxBadxBaFxdxxdxBaGxdxx=FxGx
262 261 mpteq2dva φaA<aa<BxBadxBaFxdxxdxBaGxdxx=xBaFxGx
263 247 262 eqtrid φaA<aa<ByBadxBaFxdxydxBaGxdxy=xBaFxGx
264 263 oveq1d φaA<aa<ByBadxBaFxdxydxBaGxdxylimB=xBaFxGxlimB
265 231 264 eleqtrrd φaA<aa<BCyBadxBaFxdxydxBaGxdxylimB
266 82 84 87 88 89 133 159 186 192 196 213 265 lhop1 φaA<aa<BCyBaxBaFxyxBaGxylimB
267 nffvmpt1 _xxBaFxy
268 nffvmpt1 _xxBaGxy
269 267 238 268 nfov _xxBaFxyxBaGxy
270 nfcv _yxBaFxxxBaGxx
271 fveq2 y=xxBaFxy=xBaFxx
272 fveq2 y=xxBaGxy=xBaGxx
273 271 272 oveq12d y=xxBaFxyxBaGxy=xBaFxxxBaGxx
274 269 270 273 cbvmpt yBaxBaFxyxBaGxy=xBaxBaFxxxBaGxx
275 fvex FxV
276 eqid xBaFx=xBaFx
277 276 fvmpt2 xBaFxVxBaFxx=Fx
278 34 275 277 sylancl φaA<aa<BxBaxBaFxx=Fx
279 fvex GxV
280 eqid xBaGx=xBaGx
281 280 fvmpt2 xBaGxVxBaGxx=Gx
282 34 279 281 sylancl φaA<aa<BxBaxBaGxx=Gx
283 278 282 oveq12d φaA<aa<BxBaxBaFxxxBaGxx=FxGx
284 283 mpteq2dva φaA<aa<BxBaxBaFxxxBaGxx=xBaFxGx
285 274 284 eqtrid φaA<aa<ByBaxBaFxyxBaGxy=xBaFxGx
286 285 oveq1d φaA<aa<ByBaxBaFxyxBaGxylimB=xBaFxGxlimB
287 266 286 eleqtrd φaA<aa<BCxBaFxGxlimB
288 negeq x=zx=z
289 288 fveq2d x=zFx=Fz
290 288 fveq2d x=zGx=Gz
291 289 290 oveq12d x=zFxGx=FzGz
292 82 adantr φaA<aa<BzaBB
293 eliooord zaBa<zz<B
294 293 adantl φaA<aa<BzaBa<zz<B
295 294 simprd φaA<aa<BzaBz<B
296 24 22 ltnegd φaA<aa<BzaBz<BB<z
297 295 296 mpbid φaA<aa<BzaBB<z
298 292 297 gtned φaA<aa<BzaBzB
299 298 neneqd φaA<aa<BzaB¬z=B
300 299 pm2.21d φaA<aa<BzaBz=BFzGz=C
301 300 impr φaA<aa<BzaBz=BFzGz=C
302 28 68 81 287 291 301 limcco φaA<aa<BCzaBFzGzlimB
303 24 recnd φaA<aa<BzaBz
304 303 negnegd φaA<aa<BzaBz=z
305 304 fveq2d φaA<aa<BzaBFz=Fz
306 304 fveq2d φaA<aa<BzaBGz=Gz
307 305 306 oveq12d φaA<aa<BzaBFzGz=FzGz
308 307 mpteq2dva φaA<aa<BzaBFzGz=zaBFzGz
309 308 oveq1d φaA<aa<BzaBFzGzlimB=zaBFzGzlimB
310 47 resmptd φaA<aa<BzABFzGzaB=zaBFzGz
311 310 oveq1d φaA<aa<BzABFzGzaBlimB=zaBFzGzlimB
312 fss F:ABF:AB
313 94 57 312 sylancl φaA<aa<BF:AB
314 313 ffvelcdmda φaA<aa<BzABFz
315 59 ffvelcdmda φaA<aa<BzABGz
316 10 ad2antrr φaA<aa<BzAB¬0ranG
317 56 ffnd φaA<aa<BGFnAB
318 fnfvelrn GFnABzABGzranG
319 317 318 sylan φaA<aa<BzABGzranG
320 eleq1 Gz=0GzranG0ranG
321 319 320 syl5ibcom φaA<aa<BzABGz=00ranG
322 321 necon3bd φaA<aa<BzAB¬0ranGGz0
323 316 322 mpd φaA<aa<BzABGz0
324 314 315 323 divcld φaA<aa<BzABFzGz
325 324 fmpttd φaA<aa<BzABFzGz:AB
326 ioossre AB
327 326 57 sstri AB
328 327 a1i φaA<aa<BAB
329 eqid TopOpenfld𝑡ABB=TopOpenfld𝑡ABB
330 ssun2 BaBB
331 snssg BBaBBBaBB
332 78 331 syl φaA<aa<BBaBBBaBB
333 330 332 mpbiri φaA<aa<BBaBB
334 105 cnfldtopon TopOpenfldTopOn
335 326 a1i φaA<aa<BAB
336 78 snssd φaA<aa<BB
337 335 336 unssd φaA<aa<BABB
338 337 57 sstrdi φaA<aa<BABB
339 resttopon TopOpenfldTopOnABBTopOpenfld𝑡ABBTopOnABB
340 334 338 339 sylancr φaA<aa<BTopOpenfld𝑡ABBTopOnABB
341 topontop TopOpenfld𝑡ABBTopOnABBTopOpenfld𝑡ABBTop
342 340 341 syl φaA<aa<BTopOpenfld𝑡ABBTop
343 indi a+∞ABB=a+∞ABa+∞B
344 pnfxr +∞*
345 344 a1i φaA<aa<B+∞*
346 14 adantr φaA<aa<BB*
347 iooin a*+∞*A*B*a+∞AB=ifaAAaif+∞B+∞B
348 43 345 42 346 347 syl22anc φaA<aa<Ba+∞AB=ifaAAaif+∞B+∞B
349 xrltnle A*a*A<a¬aA
350 42 43 349 syl2anc φaA<aa<BA<a¬aA
351 44 350 mpbid φaA<aa<B¬aA
352 351 iffalsed φaA<aa<BifaAAa=a
353 78 ltpnfd φaA<aa<BB<+∞
354 xrltnle B*+∞*B<+∞¬+∞B
355 346 344 354 sylancl φaA<aa<BB<+∞¬+∞B
356 353 355 mpbid φaA<aa<B¬+∞B
357 356 iffalsed φaA<aa<Bif+∞B+∞B=B
358 352 357 oveq12d φaA<aa<BifaAAaif+∞B+∞B=aB
359 348 358 eqtrd φaA<aa<Ba+∞AB=aB
360 elioopnf a*Ba+∞Ba<B
361 43 360 syl φaA<aa<BBa+∞Ba<B
362 78 85 361 mpbir2and φaA<aa<BBa+∞
363 362 snssd φaA<aa<BBa+∞
364 sseqin2 Ba+∞a+∞B=B
365 363 364 sylib φaA<aa<Ba+∞B=B
366 359 365 uneq12d φaA<aa<Ba+∞ABa+∞B=aBB
367 343 366 eqtrid φaA<aa<Ba+∞ABB=aBB
368 retop topGenran.Top
369 reex V
370 369 ssex ABBABBV
371 337 370 syl φaA<aa<BABBV
372 iooretop a+∞topGenran.
373 372 a1i φaA<aa<Ba+∞topGenran.
374 elrestr topGenran.TopABBVa+∞topGenran.a+∞ABBtopGenran.𝑡ABB
375 368 371 373 374 mp3an2i φaA<aa<Ba+∞ABBtopGenran.𝑡ABB
376 367 375 eqeltrrd φaA<aa<BaBBtopGenran.𝑡ABB
377 eqid topGenran.=topGenran.
378 105 377 rerest ABBTopOpenfld𝑡ABB=topGenran.𝑡ABB
379 337 378 syl φaA<aa<BTopOpenfld𝑡ABB=topGenran.𝑡ABB
380 376 379 eleqtrrd φaA<aa<BaBBTopOpenfld𝑡ABB
381 isopn3i TopOpenfld𝑡ABBTopaBBTopOpenfld𝑡ABBintTopOpenfld𝑡ABBaBB=aBB
382 342 380 381 syl2anc φaA<aa<BintTopOpenfld𝑡ABBaBB=aBB
383 333 382 eleqtrrd φaA<aa<BBintTopOpenfld𝑡ABBaBB
384 325 47 328 105 329 383 limcres φaA<aa<BzABFzGzaBlimB=zABFzGzlimB
385 309 311 384 3eqtr2d φaA<aa<BzaBFzGzlimB=zABFzGzlimB
386 302 385 eleqtrd φaA<aa<BCzABFzGzlimB
387 18 386 rexlimddv φCzABFzGzlimB