Metamath Proof Explorer


Theorem prdsxmetlem

Description: The product metric is an extended metric. (Contributed by Mario Carneiro, 20-Aug-2015)

Ref Expression
Hypotheses prdsdsf.y Y = S 𝑠 x I R
prdsdsf.b B = Base Y
prdsdsf.v V = Base R
prdsdsf.e E = dist R V × V
prdsdsf.d D = dist Y
prdsdsf.s φ S W
prdsdsf.i φ I X
prdsdsf.r φ x I R Z
prdsdsf.m φ x I E ∞Met V
Assertion prdsxmetlem φ D ∞Met B

Proof

Step Hyp Ref Expression
1 prdsdsf.y Y = S 𝑠 x I R
2 prdsdsf.b B = Base Y
3 prdsdsf.v V = Base R
4 prdsdsf.e E = dist R V × V
5 prdsdsf.d D = dist Y
6 prdsdsf.s φ S W
7 prdsdsf.i φ I X
8 prdsdsf.r φ x I R Z
9 prdsdsf.m φ x I E ∞Met V
10 2 fvexi B V
11 10 a1i φ B V
12 1 2 3 4 5 6 7 8 9 prdsdsf φ D : B × B 0 +∞
13 iccssxr 0 +∞ *
14 fss D : B × B 0 +∞ 0 +∞ * D : B × B *
15 12 13 14 sylancl φ D : B × B *
16 12 fovrnda φ f B g B f D g 0 +∞
17 elxrge0 f D g 0 +∞ f D g * 0 f D g
18 17 simprbi f D g 0 +∞ 0 f D g
19 16 18 syl φ f B g B 0 f D g
20 6 adantr φ f B g B S W
21 7 adantr φ f B g B I X
22 8 ralrimiva φ x I R Z
23 22 adantr φ f B g B x I R Z
24 simprl φ f B g B f B
25 simprr φ f B g B g B
26 1 2 20 21 23 24 25 3 4 5 prdsdsval3 φ f B g B f D g = sup ran x I f x E g x 0 * <
27 26 breq1d φ f B g B f D g 0 sup ran x I f x E g x 0 * < 0
28 9 adantlr φ f B g B x I E ∞Met V
29 1 2 20 21 23 3 24 prdsbascl φ f B g B x I f x V
30 29 r19.21bi φ f B g B x I f x V
31 1 2 20 21 23 3 25 prdsbascl φ f B g B x I g x V
32 31 r19.21bi φ f B g B x I g x V
33 xmetcl E ∞Met V f x V g x V f x E g x *
34 28 30 32 33 syl3anc φ f B g B x I f x E g x *
35 34 fmpttd φ f B g B x I f x E g x : I *
36 35 frnd φ f B g B ran x I f x E g x *
37 0xr 0 *
38 37 a1i φ f B g B 0 *
39 38 snssd φ f B g B 0 *
40 36 39 unssd φ f B g B ran x I f x E g x 0 *
41 supxrleub ran x I f x E g x 0 * 0 * sup ran x I f x E g x 0 * < 0 z ran x I f x E g x 0 z 0
42 40 37 41 sylancl φ f B g B sup ran x I f x E g x 0 * < 0 z ran x I f x E g x 0 z 0
43 0le0 0 0
44 c0ex 0 V
45 breq1 z = 0 z 0 0 0
46 44 45 ralsn z 0 z 0 0 0
47 43 46 mpbir z 0 z 0
48 ralunb z ran x I f x E g x 0 z 0 z ran x I f x E g x z 0 z 0 z 0
49 47 48 mpbiran2 z ran x I f x E g x 0 z 0 z ran x I f x E g x z 0
50 ovex f x E g x V
51 50 rgenw x I f x E g x V
52 eqid x I f x E g x = x I f x E g x
53 breq1 z = f x E g x z 0 f x E g x 0
54 52 53 ralrnmptw x I f x E g x V z ran x I f x E g x z 0 x I f x E g x 0
55 51 54 ax-mp z ran x I f x E g x z 0 x I f x E g x 0
56 49 55 bitri z ran x I f x E g x 0 z 0 x I f x E g x 0
57 xmetge0 E ∞Met V f x V g x V 0 f x E g x
58 28 30 32 57 syl3anc φ f B g B x I 0 f x E g x
59 58 biantrud φ f B g B x I f x E g x 0 f x E g x 0 0 f x E g x
60 xrletri3 f x E g x * 0 * f x E g x = 0 f x E g x 0 0 f x E g x
61 34 37 60 sylancl φ f B g B x I f x E g x = 0 f x E g x 0 0 f x E g x
62 xmeteq0 E ∞Met V f x V g x V f x E g x = 0 f x = g x
63 28 30 32 62 syl3anc φ f B g B x I f x E g x = 0 f x = g x
64 59 61 63 3bitr2d φ f B g B x I f x E g x 0 f x = g x
65 64 ralbidva φ f B g B x I f x E g x 0 x I f x = g x
66 eqid x I R = x I R
67 66 fnmpt x I R Z x I R Fn I
68 22 67 syl φ x I R Fn I
69 68 adantr φ f B g B x I R Fn I
70 1 2 20 21 69 24 prdsbasfn φ f B g B f Fn I
71 1 2 20 21 69 25 prdsbasfn φ f B g B g Fn I
72 eqfnfv f Fn I g Fn I f = g x I f x = g x
73 70 71 72 syl2anc φ f B g B f = g x I f x = g x
74 65 73 bitr4d φ f B g B x I f x E g x 0 f = g
75 56 74 syl5bb φ f B g B z ran x I f x E g x 0 z 0 f = g
76 27 42 75 3bitrd φ f B g B f D g 0 f = g
77 26 3adantr3 φ f B g B h B f D g = sup ran x I f x E g x 0 * <
78 77 3adant3 φ f B g B h B h D f h D g f D g = sup ran x I f x E g x 0 * <
79 9 3ad2antl1 φ f B g B h B h D f h D g x I E ∞Met V
80 29 3adantr3 φ f B g B h B x I f x V
81 80 3adant3 φ f B g B h B h D f h D g x I f x V
82 81 r19.21bi φ f B g B h B h D f h D g x I f x V
83 31 3adantr3 φ f B g B h B x I g x V
84 83 3adant3 φ f B g B h B h D f h D g x I g x V
85 84 r19.21bi φ f B g B h B h D f h D g x I g x V
86 79 82 85 33 syl3anc φ f B g B h B h D f h D g x I f x E g x *
87 6 3ad2ant1 φ f B g B h B h D f h D g S W
88 7 3ad2ant1 φ f B g B h B h D f h D g I X
89 22 3ad2ant1 φ f B g B h B h D f h D g x I R Z
90 simp23 φ f B g B h B h D f h D g h B
91 1 2 87 88 89 3 90 prdsbascl φ f B g B h B h D f h D g x I h x V
92 91 r19.21bi φ f B g B h B h D f h D g x I h x V
93 xmetcl E ∞Met V h x V f x V h x E f x *
94 79 92 82 93 syl3anc φ f B g B h B h D f h D g x I h x E f x *
95 simp3l φ f B g B h B h D f h D g h D f
96 95 adantr φ f B g B h B h D f h D g x I h D f
97 xmetge0 E ∞Met V h x V f x V 0 h x E f x
98 79 92 82 97 syl3anc φ f B g B h B h D f h D g x I 0 h x E f x
99 94 fmpttd φ f B g B h B h D f h D g x I h x E f x : I *
100 99 frnd φ f B g B h B h D f h D g ran x I h x E f x *
101 37 a1i φ f B g B h B h D f h D g 0 *
102 101 snssd φ f B g B h B h D f h D g 0 *
103 100 102 unssd φ f B g B h B h D f h D g ran x I h x E f x 0 *
104 ssun1 ran x I h x E f x ran x I h x E f x 0
105 ovex h x E f x V
106 105 elabrex x I h x E f x z | x I z = h x E f x
107 106 adantl φ f B g B h B h D f h D g x I h x E f x z | x I z = h x E f x
108 eqid x I h x E f x = x I h x E f x
109 108 rnmpt ran x I h x E f x = z | x I z = h x E f x
110 107 109 eleqtrrdi φ f B g B h B h D f h D g x I h x E f x ran x I h x E f x
111 104 110 sselid φ f B g B h B h D f h D g x I h x E f x ran x I h x E f x 0
112 supxrub ran x I h x E f x 0 * h x E f x ran x I h x E f x 0 h x E f x sup ran x I h x E f x 0 * <
113 103 111 112 syl2an2r φ f B g B h B h D f h D g x I h x E f x sup ran x I h x E f x 0 * <
114 simp21 φ f B g B h B h D f h D g f B
115 1 2 87 88 89 90 114 3 4 5 prdsdsval3 φ f B g B h B h D f h D g h D f = sup ran x I h x E f x 0 * <
116 115 adantr φ f B g B h B h D f h D g x I h D f = sup ran x I h x E f x 0 * <
117 113 116 breqtrrd φ f B g B h B h D f h D g x I h x E f x h D f
118 xrrege0 h x E f x * h D f 0 h x E f x h x E f x h D f h x E f x
119 94 96 98 117 118 syl22anc φ f B g B h B h D f h D g x I h x E f x
120 xmetcl E ∞Met V h x V g x V h x E g x *
121 79 92 85 120 syl3anc φ f B g B h B h D f h D g x I h x E g x *
122 simp3r φ f B g B h B h D f h D g h D g
123 122 adantr φ f B g B h B h D f h D g x I h D g
124 xmetge0 E ∞Met V h x V g x V 0 h x E g x
125 79 92 85 124 syl3anc φ f B g B h B h D f h D g x I 0 h x E g x
126 121 fmpttd φ f B g B h B h D f h D g x I h x E g x : I *
127 126 frnd φ f B g B h B h D f h D g ran x I h x E g x *
128 127 102 unssd φ f B g B h B h D f h D g ran x I h x E g x 0 *
129 ssun1 ran x I h x E g x ran x I h x E g x 0
130 ovex h x E g x V
131 130 elabrex x I h x E g x z | x I z = h x E g x
132 131 adantl φ f B g B h B h D f h D g x I h x E g x z | x I z = h x E g x
133 eqid x I h x E g x = x I h x E g x
134 133 rnmpt ran x I h x E g x = z | x I z = h x E g x
135 132 134 eleqtrrdi φ f B g B h B h D f h D g x I h x E g x ran x I h x E g x
136 129 135 sselid φ f B g B h B h D f h D g x I h x E g x ran x I h x E g x 0
137 supxrub ran x I h x E g x 0 * h x E g x ran x I h x E g x 0 h x E g x sup ran x I h x E g x 0 * <
138 128 136 137 syl2an2r φ f B g B h B h D f h D g x I h x E g x sup ran x I h x E g x 0 * <
139 simp22 φ f B g B h B h D f h D g g B
140 1 2 87 88 89 90 139 3 4 5 prdsdsval3 φ f B g B h B h D f h D g h D g = sup ran x I h x E g x 0 * <
141 140 adantr φ f B g B h B h D f h D g x I h D g = sup ran x I h x E g x 0 * <
142 138 141 breqtrrd φ f B g B h B h D f h D g x I h x E g x h D g
143 xrrege0 h x E g x * h D g 0 h x E g x h x E g x h D g h x E g x
144 121 123 125 142 143 syl22anc φ f B g B h B h D f h D g x I h x E g x
145 119 144 readdcld φ f B g B h B h D f h D g x I h x E f x + h x E g x
146 79 82 85 57 syl3anc φ f B g B h B h D f h D g x I 0 f x E g x
147 xmettri2 E ∞Met V h x V f x V g x V f x E g x h x E f x + 𝑒 h x E g x
148 79 92 82 85 147 syl13anc φ f B g B h B h D f h D g x I f x E g x h x E f x + 𝑒 h x E g x
149 119 144 rexaddd φ f B g B h B h D f h D g x I h x E f x + 𝑒 h x E g x = h x E f x + h x E g x
150 148 149 breqtrd φ f B g B h B h D f h D g x I f x E g x h x E f x + h x E g x
151 xrrege0 f x E g x * h x E f x + h x E g x 0 f x E g x f x E g x h x E f x + h x E g x f x E g x
152 86 145 146 150 151 syl22anc φ f B g B h B h D f h D g x I f x E g x
153 readdcl h D f h D g h D f + h D g
154 153 3ad2ant3 φ f B g B h B h D f h D g h D f + h D g
155 154 adantr φ f B g B h B h D f h D g x I h D f + h D g
156 119 144 96 123 117 142 le2addd φ f B g B h B h D f h D g x I h x E f x + h x E g x h D f + h D g
157 152 145 155 150 156 letrd φ f B g B h B h D f h D g x I f x E g x h D f + h D g
158 157 ralrimiva φ f B g B h B h D f h D g x I f x E g x h D f + h D g
159 86 ralrimiva φ f B g B h B h D f h D g x I f x E g x *
160 breq1 z = f x E g x z h D f + h D g f x E g x h D f + h D g
161 52 160 ralrnmptw x I f x E g x * z ran x I f x E g x z h D f + h D g x I f x E g x h D f + h D g
162 159 161 syl φ f B g B h B h D f h D g z ran x I f x E g x z h D f + h D g x I f x E g x h D f + h D g
163 158 162 mpbird φ f B g B h B h D f h D g z ran x I f x E g x z h D f + h D g
164 12 3ad2ant1 φ f B g B h B h D f h D g D : B × B 0 +∞
165 164 90 114 fovrnd φ f B g B h B h D f h D g h D f 0 +∞
166 elxrge0 h D f 0 +∞ h D f * 0 h D f
167 166 simprbi h D f 0 +∞ 0 h D f
168 165 167 syl φ f B g B h B h D f h D g 0 h D f
169 164 90 139 fovrnd φ f B g B h B h D f h D g h D g 0 +∞
170 elxrge0 h D g 0 +∞ h D g * 0 h D g
171 170 simprbi h D g 0 +∞ 0 h D g
172 169 171 syl φ f B g B h B h D f h D g 0 h D g
173 95 122 168 172 addge0d φ f B g B h B h D f h D g 0 h D f + h D g
174 breq1 z = 0 z h D f + h D g 0 h D f + h D g
175 44 174 ralsn z 0 z h D f + h D g 0 h D f + h D g
176 173 175 sylibr φ f B g B h B h D f h D g z 0 z h D f + h D g
177 ralunb z ran x I f x E g x 0 z h D f + h D g z ran x I f x E g x z h D f + h D g z 0 z h D f + h D g
178 163 176 177 sylanbrc φ f B g B h B h D f h D g z ran x I f x E g x 0 z h D f + h D g
179 40 3adantr3 φ f B g B h B ran x I f x E g x 0 *
180 179 3adant3 φ f B g B h B h D f h D g ran x I f x E g x 0 *
181 154 rexrd φ f B g B h B h D f h D g h D f + h D g *
182 supxrleub ran x I f x E g x 0 * h D f + h D g * sup ran x I f x E g x 0 * < h D f + h D g z ran x I f x E g x 0 z h D f + h D g
183 180 181 182 syl2anc φ f B g B h B h D f h D g sup ran x I f x E g x 0 * < h D f + h D g z ran x I f x E g x 0 z h D f + h D g
184 178 183 mpbird φ f B g B h B h D f h D g sup ran x I f x E g x 0 * < h D f + h D g
185 78 184 eqbrtrd φ f B g B h B h D f h D g f D g h D f + h D g
186 11 15 19 76 185 isxmet2d φ D ∞Met B