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 φ A *
lhop2.b φ B
lhop2.l φ A < B
lhop2.f φ F : A B
lhop2.g φ G : A B
lhop2.if φ dom F = A B
lhop2.ig φ dom G = A B
lhop2.f0 φ 0 F lim B
lhop2.g0 φ 0 G lim B
lhop2.gn0 φ ¬ 0 ran G
lhop2.gd0 φ ¬ 0 ran G
lhop2.c φ C z A B F z G z lim B
Assertion lhop2 φ C z A B F z G z lim B

Proof

Step Hyp Ref Expression
1 lhop2.a φ A *
2 lhop2.b φ B
3 lhop2.l φ A < B
4 lhop2.f φ F : A B
5 lhop2.g φ G : A B
6 lhop2.if φ dom F = A B
7 lhop2.ig φ dom G = A B
8 lhop2.f0 φ 0 F lim B
9 lhop2.g0 φ 0 G lim B
10 lhop2.gn0 φ ¬ 0 ran G
11 lhop2.gd0 φ ¬ 0 ran G
12 lhop2.c φ C z A B F z G z lim B
13 qssre
14 2 rexrd φ B *
15 qbtwnxr A * B * A < B a A < a a < B
16 1 14 3 15 syl3anc φ a A < a a < B
17 ssrexv a A < a a < B a A < a a < B
18 13 16 17 mpsyl φ a A < a a < B
19 simpr φ a A < a a < B z a B z a B
20 simprl φ a A < a a < B a
21 20 adantr φ a A < a a < B z a B a
22 2 ad2antrr φ a A < a a < B z a B B
23 elioore z a B z
24 23 adantl φ a A < a a < B z a B z
25 iooneg a B z z a B z B a
26 21 22 24 25 syl3anc φ a A < a a < B z a B z a B z B a
27 19 26 mpbid φ a A < a a < B z a B z B a
28 27 adantrr φ a A < a a < B z a B z B z B a
29 4 ad2antrr φ a A < a a < B x B a F : A B
30 elioore x B a x
31 30 adantl φ a A < a a < B x B a x
32 31 recnd φ a A < a a < B x B a x
33 32 negnegd φ a A < a a < B x B a x = x
34 simpr φ a A < a a < B x B a x B a
35 33 34 eqeltrd φ a A < a a < B x B a x B a
36 20 adantr φ a A < a a < B x B a a
37 2 ad2antrr φ a A < a a < B x B a B
38 31 renegcld φ a A < a a < B x B a x
39 iooneg a B x x a B x B a
40 36 37 38 39 syl3anc φ a A < a a < B x B a x a B x B a
41 35 40 mpbird φ a A < a a < B x B a x a B
42 1 adantr φ a A < a a < B A *
43 20 rexrd φ a A < a a < B a *
44 simprrl φ a A < a a < B A < a
45 42 43 44 xrltled φ a A < a a < B A a
46 iooss1 A * A a a B A B
47 42 45 46 syl2anc φ a A < a a < B a B A B
48 47 sselda φ a A < a a < B x a B x A B
49 41 48 syldan φ a A < a a < B x B a x A B
50 29 49 ffvelrnd φ a A < a a < B x B a F x
51 50 recnd φ a A < a a < B x B a F x
52 5 ad2antrr φ a A < a a < B x B a G : A B
53 52 49 ffvelrnd φ a A < a a < B x B a G x
54 53 recnd φ a A < a a < B x B a G x
55 10 ad2antrr φ a A < a a < B x B a ¬ 0 ran G
56 5 adantr φ a A < a a < B G : A B
57 ax-resscn
58 fss G : A B G : A B
59 56 57 58 sylancl φ a A < a a < B G : A B
60 59 adantr φ a A < a a < B x B a G : A B
61 60 ffnd φ a A < a a < B x B a G Fn A B
62 fnfvelrn G Fn A B x A B G x ran G
63 61 49 62 syl2anc φ a A < a a < B x B a G x ran G
64 eleq1 G x = 0 G x ran G 0 ran G
65 63 64 syl5ibcom φ a A < a a < B x B a G x = 0 0 ran G
66 65 necon3bd φ a A < a a < B x B a ¬ 0 ran G G x 0
67 55 66 mpd φ a A < a a < B x B a G x 0
68 51 54 67 divcld φ a A < a a < B x B a F x G x
69 limcresi z z lim B z z a B lim B
70 ioossre a B
71 resmpt a B z z a B = z a B z
72 70 71 ax-mp z z a B = z a B z
73 72 oveq1i z z a B lim B = z a B z lim B
74 69 73 sseqtri z z lim B z a B z lim B
75 eqid z z = z z
76 75 negcncf z z : cn
77 57 76 mp1i φ a A < a a < B z z : cn
78 2 adantr φ a A < a a < B B
79 negeq z = B z = B
80 77 78 79 cnmptlimc φ a A < a a < B B z z lim B
81 74 80 sselid φ a A < a a < B B z a B z lim B
82 78 renegcld φ a A < a a < B B
83 20 renegcld φ a A < a a < B a
84 83 rexrd φ a A < a a < B a *
85 simprrr φ a A < a a < B a < B
86 20 78 ltnegd φ a A < a a < B a < B B < a
87 85 86 mpbid φ a A < a a < B B < a
88 50 fmpttd φ a A < a a < B x B a F x : B a
89 53 fmpttd φ a A < a a < B x B a G x : B a
90 reelprrecn
91 90 a1i φ a A < a a < B
92 neg1cn 1
93 92 a1i φ a A < a a < B x B a 1
94 4 adantr φ a A < a a < B F : A B
95 94 ffvelrnda φ a A < a a < B y A B F y
96 95 recnd φ a A < a a < B y A B F y
97 fvexd φ a A < a a < B y A B F y V
98 1cnd φ a A < a a < B x B a 1
99 simpr φ a A < a a < B x x
100 99 recnd φ a A < a a < B x x
101 1cnd φ a A < a a < B x 1
102 91 dvmptid φ a A < a a < B dx x d x = x 1
103 ioossre B a
104 103 a1i φ a A < a a < B B a
105 eqid TopOpen fld = TopOpen fld
106 105 tgioo2 topGen ran . = TopOpen fld 𝑡
107 iooretop B a topGen ran .
108 107 a1i φ a A < a a < B B a topGen ran .
109 91 100 101 102 104 106 105 108 dvmptres φ a A < a a < B dx B a x d x = x B a 1
110 91 32 98 109 dvmptneg φ a A < a a < B dx B a x d x = x B a 1
111 94 feqmptd φ a A < a a < B F = y A B F y
112 111 oveq2d φ a A < a a < B D F = dy A B F y d y
113 dvf F : dom F
114 6 adantr φ a A < a a < B dom F = A B
115 114 feq2d φ a A < a a < B F : dom F F : A B
116 113 115 mpbii φ a A < a a < B F : A B
117 116 feqmptd φ a A < a a < B D F = y A B F y
118 112 117 eqtr3d φ a A < a a < B dy A B F y d y = y A B F y
119 fveq2 y = x F y = F x
120 fveq2 y = x F y = F x
121 91 91 49 93 96 97 110 118 119 120 dvmptco φ a A < a a < B dx B a F x d x = x B a F x -1
122 116 adantr φ a A < a a < B x B a F : A B
123 122 49 ffvelrnd φ a A < a a < B x B a F x
124 123 93 mulcomd φ a A < a a < B x B a F x -1 = -1 F x
125 123 mulm1d φ a A < a a < B x B a -1 F x = F x
126 124 125 eqtrd φ a A < a a < B x B a F x -1 = F x
127 126 mpteq2dva φ a A < a a < B x B a F x -1 = x B a F x
128 121 127 eqtrd φ a A < a a < B dx B a F x d x = x B a F x
129 128 dmeqd φ a A < a a < B dom dx B a F x d x = dom x B a F x
130 negex F x V
131 eqid x B a F x = x B a F x
132 130 131 dmmpti dom x B a F x = B a
133 129 132 eqtrdi φ a A < a a < B dom dx B a F x d x = B a
134 56 ffvelrnda φ a A < a a < B y A B G y
135 134 recnd φ a A < a a < B y A B G y
136 fvexd φ a A < a a < B y A B G y V
137 56 feqmptd φ a A < a a < B G = y A B G y
138 137 oveq2d φ a A < a a < B D G = dy A B G y d y
139 dvf G : dom G
140 7 adantr φ a A < a a < B dom G = A B
141 140 feq2d φ a A < a a < B G : dom G G : A B
142 139 141 mpbii φ a A < a a < B G : A B
143 142 feqmptd φ a A < a a < B D G = y A B G y
144 138 143 eqtr3d φ a A < a a < B dy A B G y d y = y A B G y
145 fveq2 y = x G y = G x
146 fveq2 y = x G y = G x
147 91 91 49 93 135 136 110 144 145 146 dvmptco φ a A < a a < B dx B a G x d x = x B a G x -1
148 142 adantr φ a A < a a < B x B a G : A B
149 148 49 ffvelrnd φ a A < a a < B x B a G x
150 149 93 mulcomd φ a A < a a < B x B a G x -1 = -1 G x
151 149 mulm1d φ a A < a a < B x B a -1 G x = G x
152 150 151 eqtrd φ a A < a a < B x B a G x -1 = G x
153 152 mpteq2dva φ a A < a a < B x B a G x -1 = x B a G x
154 147 153 eqtrd φ a A < a a < B dx B a G x d x = x B a G x
155 154 dmeqd φ a A < a a < B dom dx B a G x d x = dom x B a G x
156 negex G x V
157 eqid x B a G x = x B a G x
158 156 157 dmmpti dom x B a G x = B a
159 155 158 eqtrdi φ a A < a a < B dom dx B a G x d x = B a
160 49 adantrr φ a A < a a < B x B a x B x A B
161 limcresi x x lim B x x B a lim B
162 resmpt B a x x B a = x B a x
163 103 162 ax-mp x x B a = x B a x
164 163 oveq1i x x B a lim B = x B a x lim B
165 161 164 sseqtri x x lim B x B a x lim B
166 78 recnd φ a A < a a < B B
167 166 negnegd φ a A < a a < B B = B
168 eqid x x = x x
169 168 negcncf x x : cn
170 57 169 mp1i φ a A < a a < B x x : cn
171 negeq x = B x = B
172 170 82 171 cnmptlimc φ a A < a a < B B x x lim B
173 167 172 eqeltrrd φ a A < a a < B B x x lim B
174 165 173 sselid φ a A < a a < B B x B a x lim B
175 8 adantr φ a A < a a < B 0 F lim B
176 111 oveq1d φ a A < a a < B F lim B = y A B F y lim B
177 175 176 eleqtrd φ a A < a a < B 0 y A B F y lim B
178 eliooord x B a B < x x < a
179 178 adantl φ a A < a a < B x B a B < x x < a
180 179 simpld φ a A < a a < B x B a B < x
181 37 31 180 ltnegcon1d φ a A < a a < B x B a x < B
182 38 181 ltned φ a A < a a < B x B a x B
183 182 neneqd φ a A < a a < B x B a ¬ x = B
184 183 pm2.21d φ a A < a a < B x B a x = B F x = 0
185 184 impr φ a A < a a < B x B a x = B F x = 0
186 160 96 174 177 119 185 limcco φ a A < a a < B 0 x B a F x lim B
187 9 adantr φ a A < a a < B 0 G lim B
188 137 oveq1d φ a A < a a < B G lim B = y A B G y lim B
189 187 188 eleqtrd φ a A < a a < B 0 y A B G y lim B
190 183 pm2.21d φ a A < a a < B x B a x = B G x = 0
191 190 impr φ a A < a a < B x B a x = B G x = 0
192 160 135 174 189 145 191 limcco φ a A < a a < B 0 x B a G x lim B
193 63 fmpttd φ a A < a a < B x B a G x : B a ran G
194 193 frnd φ a A < a a < B ran x B a G x ran G
195 10 adantr φ a A < a a < B ¬ 0 ran G
196 194 195 ssneldd φ a A < a a < B ¬ 0 ran x B a G x
197 11 adantr φ a A < a a < B ¬ 0 ran G
198 154 rneqd φ a A < a a < B ran dx B a G x d x = ran x B a G x
199 198 eleq2d φ a A < a a < B 0 ran dx B a G x d x 0 ran x B a G x
200 157 156 elrnmpti 0 ran x B a G x x B a 0 = G x
201 eqcom 0 = G x G x = 0
202 149 negeq0d φ a A < a a < B x B a G x = 0 G x = 0
203 148 ffnd φ a A < a a < B x B a G Fn A B
204 fnfvelrn G Fn A B x A B G x ran G
205 203 49 204 syl2anc φ a A < a a < B x B a G x ran G
206 eleq1 G x = 0 G x ran G 0 ran G
207 205 206 syl5ibcom φ a A < a a < B x B a G x = 0 0 ran G
208 202 207 sylbird φ a A < a a < B x B a G x = 0 0 ran G
209 201 208 syl5bi φ a A < a a < B x B a 0 = G x 0 ran G
210 209 rexlimdva φ a A < a a < B x B a 0 = G x 0 ran G
211 200 210 syl5bi φ a A < a a < B 0 ran x B a G x 0 ran G
212 199 211 sylbid φ a A < a a < B 0 ran dx B a G x d x 0 ran G
213 197 212 mtod φ a A < a a < B ¬ 0 ran dx B a G x d x
214 116 ffvelrnda φ a A < a a < B z A B F z
215 142 ffvelrnda φ a A < a a < B z A B G z
216 11 ad2antrr φ a A < a a < B z A B ¬ 0 ran G
217 142 ffnd φ a A < a a < B G Fn A B
218 fnfvelrn G Fn A B z A B G z ran G
219 217 218 sylan φ a A < a a < B z A B G z ran G
220 eleq1 G z = 0 G z ran G 0 ran G
221 219 220 syl5ibcom φ a A < a a < B z A B G z = 0 0 ran G
222 221 necon3bd φ a A < a a < B z A B ¬ 0 ran G G z 0
223 216 222 mpd φ a A < a a < B z A B G z 0
224 214 215 223 divcld φ a A < a a < B z A B F z G z
225 12 adantr φ a A < a a < B C z A B F z G z lim B
226 fveq2 z = x F z = F x
227 fveq2 z = x G z = G x
228 226 227 oveq12d z = x F z G z = F x G x
229 183 pm2.21d φ a A < a a < B x B a x = B F x G x = C
230 229 impr φ a A < a a < B x B a x = B F x G x = C
231 160 224 174 225 228 230 limcco φ a A < a a < B C x B a F x G x lim B
232 nfcv _ x
233 nfcv _ x D
234 nfmpt1 _ x x B a F x
235 232 233 234 nfov _ x dx B a F x d x
236 nfcv _ x y
237 235 236 nffv _ x dx B a F x d x y
238 nfcv _ x ÷
239 nfmpt1 _ x x B a G x
240 232 233 239 nfov _ x dx B a G x d x
241 240 236 nffv _ x dx B a G x d x y
242 237 238 241 nfov _ x dx B a F x d x y dx B a G x d x y
243 nfcv _ y dx B a F x d x x dx B a G x d x x
244 fveq2 y = x dx B a F x d x y = dx B a F x d x x
245 fveq2 y = x dx B a G x d x y = dx B a G x d x x
246 244 245 oveq12d y = x dx B a F x d x y dx B a G x d x y = dx B a F x d x x dx B a G x d x x
247 242 243 246 cbvmpt y B a dx B a F x d x y dx B a G x d x y = x B a dx B a F x d x x dx B a G x d x x
248 128 fveq1d φ a A < a a < B dx B a F x d x x = x B a F x x
249 131 fvmpt2 x B a F x V x B a F x x = F x
250 130 249 mpan2 x B a x B a F x x = F x
251 248 250 sylan9eq φ a A < a a < B x B a dx B a F x d x x = F x
252 154 fveq1d φ a A < a a < B dx B a G x d x x = x B a G x x
253 157 fvmpt2 x B a G x V x B a G x x = G x
254 156 253 mpan2 x B a x B a G x x = G x
255 252 254 sylan9eq φ a A < a a < B x B a dx B a G x d x x = G x
256 251 255 oveq12d φ a A < a a < B x B a dx B a F x d x x dx B a G x d x x = F x G x
257 11 ad2antrr φ a A < a a < B x B a ¬ 0 ran G
258 207 necon3bd φ a A < a a < B x B a ¬ 0 ran G G x 0
259 257 258 mpd φ a A < a a < B x B a G x 0
260 123 149 259 div2negd φ a A < a a < B x B a F x G x = F x G x
261 256 260 eqtrd φ a A < a a < B x B a dx B a F x d x x dx B a G x d x x = F x G x
262 261 mpteq2dva φ a A < a a < B x B a dx B a F x d x x dx B a G x d x x = x B a F x G x
263 247 262 syl5eq φ a A < a a < B y B a dx B a F x d x y dx B a G x d x y = x B a F x G x
264 263 oveq1d φ a A < a a < B y B a dx B a F x d x y dx B a G x d x y lim B = x B a F x G x lim B
265 231 264 eleqtrrd φ a A < a a < B C y B a dx B a F x d x y dx B a G x d x y lim B
266 82 84 87 88 89 133 159 186 192 196 213 265 lhop1 φ a A < a a < B C y B a x B a F x y x B a G x y lim B
267 nffvmpt1 _ x x B a F x y
268 nffvmpt1 _ x x B a G x y
269 267 238 268 nfov _ x x B a F x y x B a G x y
270 nfcv _ y x B a F x x x B a G x x
271 fveq2 y = x x B a F x y = x B a F x x
272 fveq2 y = x x B a G x y = x B a G x x
273 271 272 oveq12d y = x x B a F x y x B a G x y = x B a F x x x B a G x x
274 269 270 273 cbvmpt y B a x B a F x y x B a G x y = x B a x B a F x x x B a G x x
275 fvex F x V
276 eqid x B a F x = x B a F x
277 276 fvmpt2 x B a F x V x B a F x x = F x
278 34 275 277 sylancl φ a A < a a < B x B a x B a F x x = F x
279 fvex G x V
280 eqid x B a G x = x B a G x
281 280 fvmpt2 x B a G x V x B a G x x = G x
282 34 279 281 sylancl φ a A < a a < B x B a x B a G x x = G x
283 278 282 oveq12d φ a A < a a < B x B a x B a F x x x B a G x x = F x G x
284 283 mpteq2dva φ a A < a a < B x B a x B a F x x x B a G x x = x B a F x G x
285 274 284 syl5eq φ a A < a a < B y B a x B a F x y x B a G x y = x B a F x G x
286 285 oveq1d φ a A < a a < B y B a x B a F x y x B a G x y lim B = x B a F x G x lim B
287 266 286 eleqtrd φ a A < a a < B C x B a F x G x lim B
288 negeq x = z x = z
289 288 fveq2d x = z F x = F z
290 288 fveq2d x = z G x = G z
291 289 290 oveq12d x = z F x G x = F z G z
292 82 adantr φ a A < a a < B z a B B
293 eliooord z a B a < z z < B
294 293 adantl φ a A < a a < B z a B a < z z < B
295 294 simprd φ a A < a a < B z a B z < B
296 24 22 ltnegd φ a A < a a < B z a B z < B B < z
297 295 296 mpbid φ a A < a a < B z a B B < z
298 292 297 gtned φ a A < a a < B z a B z B
299 298 neneqd φ a A < a a < B z a B ¬ z = B
300 299 pm2.21d φ a A < a a < B z a B z = B F z G z = C
301 300 impr φ a A < a a < B z a B z = B F z G z = C
302 28 68 81 287 291 301 limcco φ a A < a a < B C z a B F z G z lim B
303 24 recnd φ a A < a a < B z a B z
304 303 negnegd φ a A < a a < B z a B z = z
305 304 fveq2d φ a A < a a < B z a B F z = F z
306 304 fveq2d φ a A < a a < B z a B G z = G z
307 305 306 oveq12d φ a A < a a < B z a B F z G z = F z G z
308 307 mpteq2dva φ a A < a a < B z a B F z G z = z a B F z G z
309 308 oveq1d φ a A < a a < B z a B F z G z lim B = z a B F z G z lim B
310 47 resmptd φ a A < a a < B z A B F z G z a B = z a B F z G z
311 310 oveq1d φ a A < a a < B z A B F z G z a B lim B = z a B F z G z lim B
312 fss F : A B F : A B
313 94 57 312 sylancl φ a A < a a < B F : A B
314 313 ffvelrnda φ a A < a a < B z A B F z
315 59 ffvelrnda φ a A < a a < B z A B G z
316 10 ad2antrr φ a A < a a < B z A B ¬ 0 ran G
317 56 ffnd φ a A < a a < B G Fn A B
318 fnfvelrn G Fn A B z A B G z ran G
319 317 318 sylan φ a A < a a < B z A B G z ran G
320 eleq1 G z = 0 G z ran G 0 ran G
321 319 320 syl5ibcom φ a A < a a < B z A B G z = 0 0 ran G
322 321 necon3bd φ a A < a a < B z A B ¬ 0 ran G G z 0
323 316 322 mpd φ a A < a a < B z A B G z 0
324 314 315 323 divcld φ a A < a a < B z A B F z G z
325 324 fmpttd φ a A < a a < B z A B F z G z : A B
326 ioossre A B
327 326 57 sstri A B
328 327 a1i φ a A < a a < B A B
329 eqid TopOpen fld 𝑡 A B B = TopOpen fld 𝑡 A B B
330 ssun2 B a B B
331 snssg B B a B B B a B B
332 78 331 syl φ a A < a a < B B a B B B a B B
333 330 332 mpbiri φ a A < a a < B B a B B
334 105 cnfldtopon TopOpen fld TopOn
335 326 a1i φ a A < a a < B A B
336 78 snssd φ a A < a a < B B
337 335 336 unssd φ a A < a a < B A B B
338 337 57 sstrdi φ a A < a a < B A B B
339 resttopon TopOpen fld TopOn A B B TopOpen fld 𝑡 A B B TopOn A B B
340 334 338 339 sylancr φ a A < a a < B TopOpen fld 𝑡 A B B TopOn A B B
341 topontop TopOpen fld 𝑡 A B B TopOn A B B TopOpen fld 𝑡 A B B Top
342 340 341 syl φ a A < a a < B TopOpen fld 𝑡 A B B Top
343 indi a +∞ A B B = a +∞ A B a +∞ B
344 pnfxr +∞ *
345 344 a1i φ a A < a a < B +∞ *
346 14 adantr φ a A < a a < B B *
347 iooin a * +∞ * A * B * a +∞ A B = if a A A a if +∞ B +∞ B
348 43 345 42 346 347 syl22anc φ a A < a a < B a +∞ A B = if a A A a if +∞ B +∞ B
349 xrltnle A * a * A < a ¬ a A
350 42 43 349 syl2anc φ a A < a a < B A < a ¬ a A
351 44 350 mpbid φ a A < a a < B ¬ a A
352 351 iffalsed φ a A < a a < B if a A A a = a
353 78 ltpnfd φ a A < a a < B B < +∞
354 xrltnle B * +∞ * B < +∞ ¬ +∞ B
355 346 344 354 sylancl φ a A < a a < B B < +∞ ¬ +∞ B
356 353 355 mpbid φ a A < a a < B ¬ +∞ B
357 356 iffalsed φ a A < a a < B if +∞ B +∞ B = B
358 352 357 oveq12d φ a A < a a < B if a A A a if +∞ B +∞ B = a B
359 348 358 eqtrd φ a A < a a < B a +∞ A B = a B
360 elioopnf a * B a +∞ B a < B
361 43 360 syl φ a A < a a < B B a +∞ B a < B
362 78 85 361 mpbir2and φ a A < a a < B B a +∞
363 362 snssd φ a A < a a < B B a +∞
364 sseqin2 B a +∞ a +∞ B = B
365 363 364 sylib φ a A < a a < B a +∞ B = B
366 359 365 uneq12d φ a A < a a < B a +∞ A B a +∞ B = a B B
367 343 366 syl5eq φ a A < a a < B a +∞ A B B = a B B
368 retop topGen ran . Top
369 reex V
370 369 ssex A B B A B B V
371 337 370 syl φ a A < a a < B A B B V
372 iooretop a +∞ topGen ran .
373 372 a1i φ a A < a a < B a +∞ topGen ran .
374 elrestr topGen ran . Top A B B V a +∞ topGen ran . a +∞ A B B topGen ran . 𝑡 A B B
375 368 371 373 374 mp3an2i φ a A < a a < B a +∞ A B B topGen ran . 𝑡 A B B
376 367 375 eqeltrrd φ a A < a a < B a B B topGen ran . 𝑡 A B B
377 eqid topGen ran . = topGen ran .
378 105 377 rerest A B B TopOpen fld 𝑡 A B B = topGen ran . 𝑡 A B B
379 337 378 syl φ a A < a a < B TopOpen fld 𝑡 A B B = topGen ran . 𝑡 A B B
380 376 379 eleqtrrd φ a A < a a < B a B B TopOpen fld 𝑡 A B B
381 isopn3i TopOpen fld 𝑡 A B B Top a B B TopOpen fld 𝑡 A B B int TopOpen fld 𝑡 A B B a B B = a B B
382 342 380 381 syl2anc φ a A < a a < B int TopOpen fld 𝑡 A B B a B B = a B B
383 333 382 eleqtrrd φ a A < a a < B B int TopOpen fld 𝑡 A B B a B B
384 325 47 328 105 329 383 limcres φ a A < a a < B z A B F z G z a B lim B = z A B F z G z lim B
385 309 311 384 3eqtr2d φ a A < a a < B z a B F z G z lim B = z A B F z G z lim B
386 302 385 eleqtrd φ a A < a a < B C z A B F z G z lim B
387 18 386 rexlimddv φ C z A B F z G z lim B