Metamath Proof Explorer


Theorem constrext2chn

Description: If a constructible number generates some subfield L of CC , then the degree of the extension of L over QQ is a power of two. (Contributed by Thierry Arnoux, 26-Oct-2025)

Ref Expression
Hypotheses constrext2chn.q Q = fld 𝑠
constrext2chn.l L = fld 𝑠 S
constrext2chn.s S = fld fldGen A
constrext2chn.a φ A Constr
Assertion constrext2chn φ n 0 L .:. Q = 2 n

Proof

Step Hyp Ref Expression
1 constrext2chn.q Q = fld 𝑠
2 constrext2chn.l L = fld 𝑠 S
3 constrext2chn.s S = fld fldGen A
4 constrext2chn.a φ A Constr
5 oveq1 o = t o j i = t j i
6 5 oveq2d o = t i + o j i = i + t j i
7 6 eqeq2d o = t y = i + o j i y = i + t j i
8 7 3anbi1d o = t y = i + o j i y = k + p l k j i l k 0 y = i + t j i y = k + p l k j i l k 0
9 oveq1 p = r p l k = r l k
10 9 oveq2d p = r k + p l k = k + r l k
11 10 eqeq2d p = r y = k + p l k y = k + r l k
12 11 3anbi2d p = r y = i + t j i y = k + p l k j i l k 0 y = i + t j i y = k + r l k j i l k 0
13 8 12 cbvrex2vw o p y = i + o j i y = k + p l k j i l k 0 t r y = i + t j i y = k + r l k j i l k 0
14 13 2rexbii k z l z o p y = i + o j i y = k + p l k j i l k 0 k z l z t r y = i + t j i y = k + r l k j i l k 0
15 id k = c k = c
16 oveq2 k = c l k = l c
17 16 oveq2d k = c r l k = r l c
18 15 17 oveq12d k = c k + r l k = c + r l c
19 18 eqeq2d k = c y = k + r l k y = c + r l c
20 16 oveq2d k = c j i l k = j i l c
21 20 fveq2d k = c j i l k = j i l c
22 21 neeq1d k = c j i l k 0 j i l c 0
23 19 22 3anbi23d k = c y = i + t j i y = k + r l k j i l k 0 y = i + t j i y = c + r l c j i l c 0
24 23 2rexbidv k = c t r y = i + t j i y = k + r l k j i l k 0 t r y = i + t j i y = c + r l c j i l c 0
25 oveq1 l = d l c = d c
26 25 oveq2d l = d r l c = r d c
27 26 oveq2d l = d c + r l c = c + r d c
28 27 eqeq2d l = d y = c + r l c y = c + r d c
29 25 oveq2d l = d j i l c = j i d c
30 29 fveq2d l = d j i l c = j i d c
31 30 neeq1d l = d j i l c 0 j i d c 0
32 28 31 3anbi23d l = d y = i + t j i y = c + r l c j i l c 0 y = i + t j i y = c + r d c j i d c 0
33 32 2rexbidv l = d t r y = i + t j i y = c + r l c j i l c 0 t r y = i + t j i y = c + r d c j i d c 0
34 24 33 cbvrex2vw k z l z t r y = i + t j i y = k + r l k j i l k 0 c z d z t r y = i + t j i y = c + r d c j i d c 0
35 14 34 bitri k z l z o p y = i + o j i y = k + p l k j i l k 0 c z d z t r y = i + t j i y = c + r d c j i d c 0
36 35 2rexbii i z j z k z l z o p y = i + o j i y = k + p l k j i l k 0 i z j z c z d z t r y = i + t j i y = c + r d c j i d c 0
37 oveq2 q = f m q = m f
38 37 fveq2d q = f m q = m f
39 38 eqeq2d q = f y k = m q y k = m f
40 39 anbi2d q = f y = i + o j i y k = m q y = i + o j i y k = m f
41 7 anbi1d o = t y = i + o j i y k = m f y = i + t j i y k = m f
42 40 41 cbvrex2vw q z o y = i + o j i y k = m q f z t y = i + t j i y k = m f
43 42 2rexbii k z m z q z o y = i + o j i y k = m q k z m z f z t y = i + t j i y k = m f
44 oveq2 k = c y k = y c
45 44 fveq2d k = c y k = y c
46 45 eqeq1d k = c y k = m f y c = m f
47 46 anbi2d k = c y = i + t j i y k = m f y = i + t j i y c = m f
48 47 2rexbidv k = c f z t y = i + t j i y k = m f f z t y = i + t j i y c = m f
49 oveq1 m = e m f = e f
50 49 fveq2d m = e m f = e f
51 50 eqeq2d m = e y c = m f y c = e f
52 51 anbi2d m = e y = i + t j i y c = m f y = i + t j i y c = e f
53 52 2rexbidv m = e f z t y = i + t j i y c = m f f z t y = i + t j i y c = e f
54 48 53 cbvrex2vw k z m z f z t y = i + t j i y k = m f c z e z f z t y = i + t j i y c = e f
55 43 54 bitri k z m z q z o y = i + o j i y k = m q c z e z f z t y = i + t j i y c = e f
56 55 2rexbii i z j z k z m z q z o y = i + o j i y k = m q i z j z c z e z f z t y = i + t j i y c = e f
57 oveq1 m = e m q = e q
58 57 fveq2d m = e m q = e q
59 58 eqeq2d m = e y l = m q y l = e q
60 59 3anbi3d m = e i l y i = j k y l = m q i l y i = j k y l = e q
61 oveq2 q = f e q = e f
62 61 fveq2d q = f e q = e f
63 62 eqeq2d q = f y l = e q y l = e f
64 63 3anbi3d q = f i l y i = j k y l = e q i l y i = j k y l = e f
65 60 64 cbvrex2vw m z q z i l y i = j k y l = m q e z f z i l y i = j k y l = e f
66 65 2rexbii k z l z m z q z i l y i = j k y l = m q k z l z e z f z i l y i = j k y l = e f
67 oveq2 k = c j k = j c
68 67 fveq2d k = c j k = j c
69 68 eqeq2d k = c y i = j k y i = j c
70 69 3anbi2d k = c i l y i = j k y l = e f i l y i = j c y l = e f
71 70 2rexbidv k = c e z f z i l y i = j k y l = e f e z f z i l y i = j c y l = e f
72 neeq2 l = d i l i d
73 oveq2 l = d y l = y d
74 73 fveq2d l = d y l = y d
75 74 eqeq1d l = d y l = e f y d = e f
76 72 75 3anbi13d l = d i l y i = j c y l = e f i d y i = j c y d = e f
77 76 2rexbidv l = d e z f z i l y i = j c y l = e f e z f z i d y i = j c y d = e f
78 71 77 cbvrex2vw k z l z e z f z i l y i = j k y l = e f c z d z e z f z i d y i = j c y d = e f
79 66 78 bitri k z l z m z q z i l y i = j k y l = m q c z d z e z f z i d y i = j c y d = e f
80 79 2rexbii i z j z k z l z m z q z i l y i = j k y l = m q i z j z c z d z e z f z i d y i = j c y d = e f
81 36 56 80 3orbi123i i z j z k z l z o p y = i + o j i y = k + p l k j i l k 0 i z j z k z m z q z o y = i + o j i y k = m q i z j z k z l z m z q z i l y i = j k y l = m q i z j z c z d z t r y = i + t j i y = c + r d c j i d c 0 i z j z c z e z f z t y = i + t j i y c = e f i z j z c z d z e z f z i d y i = j c y d = e f
82 id i = a i = a
83 oveq2 i = a j i = j a
84 83 oveq2d i = a t j i = t j a
85 82 84 oveq12d i = a i + t j i = a + t j a
86 85 eqeq2d i = a y = i + t j i y = a + t j a
87 83 fveq2d i = a j i = j a
88 87 oveq1d i = a j i d c = j a d c
89 88 fveq2d i = a j i d c = j a d c
90 89 neeq1d i = a j i d c 0 j a d c 0
91 86 90 3anbi13d i = a y = i + t j i y = c + r d c j i d c 0 y = a + t j a y = c + r d c j a d c 0
92 91 2rexbidv i = a t r y = i + t j i y = c + r d c j i d c 0 t r y = a + t j a y = c + r d c j a d c 0
93 92 2rexbidv i = a c z d z t r y = i + t j i y = c + r d c j i d c 0 c z d z t r y = a + t j a y = c + r d c j a d c 0
94 oveq1 j = b j a = b a
95 94 oveq2d j = b t j a = t b a
96 95 oveq2d j = b a + t j a = a + t b a
97 96 eqeq2d j = b y = a + t j a y = a + t b a
98 94 fveq2d j = b j a = b a
99 98 oveq1d j = b j a d c = b a d c
100 99 fveq2d j = b j a d c = b a d c
101 100 neeq1d j = b j a d c 0 b a d c 0
102 97 101 3anbi13d j = b y = a + t j a y = c + r d c j a d c 0 y = a + t b a y = c + r d c b a d c 0
103 102 2rexbidv j = b t r y = a + t j a y = c + r d c j a d c 0 t r y = a + t b a y = c + r d c b a d c 0
104 103 2rexbidv j = b c z d z t r y = a + t j a y = c + r d c j a d c 0 c z d z t r y = a + t b a y = c + r d c b a d c 0
105 93 104 cbvrex2vw i z j z c z d z t r y = i + t j i y = c + r d c j i d c 0 a z b z c z d z t r y = a + t b a y = c + r d c b a d c 0
106 86 anbi1d i = a y = i + t j i y c = e f y = a + t j a y c = e f
107 106 2rexbidv i = a f z t y = i + t j i y c = e f f z t y = a + t j a y c = e f
108 107 2rexbidv i = a c z e z f z t y = i + t j i y c = e f c z e z f z t y = a + t j a y c = e f
109 97 anbi1d j = b y = a + t j a y c = e f y = a + t b a y c = e f
110 109 2rexbidv j = b f z t y = a + t j a y c = e f f z t y = a + t b a y c = e f
111 110 2rexbidv j = b c z e z f z t y = a + t j a y c = e f c z e z f z t y = a + t b a y c = e f
112 108 111 cbvrex2vw i z j z c z e z f z t y = i + t j i y c = e f a z b z c z e z f z t y = a + t b a y c = e f
113 neeq1 i = a i d a d
114 oveq2 i = a y i = y a
115 114 fveq2d i = a y i = y a
116 115 eqeq1d i = a y i = j c y a = j c
117 113 116 3anbi12d i = a i d y i = j c y d = e f a d y a = j c y d = e f
118 117 2rexbidv i = a e z f z i d y i = j c y d = e f e z f z a d y a = j c y d = e f
119 118 2rexbidv i = a c z d z e z f z i d y i = j c y d = e f c z d z e z f z a d y a = j c y d = e f
120 oveq1 j = b j c = b c
121 120 fveq2d j = b j c = b c
122 121 eqeq2d j = b y a = j c y a = b c
123 122 3anbi2d j = b a d y a = j c y d = e f a d y a = b c y d = e f
124 123 2rexbidv j = b e z f z a d y a = j c y d = e f e z f z a d y a = b c y d = e f
125 124 2rexbidv j = b c z d z e z f z a d y a = j c y d = e f c z d z e z f z a d y a = b c y d = e f
126 119 125 cbvrex2vw i z j z c z d z e z f z i d y i = j c y d = e f a z b z c z d z e z f z a d y a = b c y d = e f
127 105 112 126 3orbi123i i z j z c z d z t r y = i + t j i y = c + r d c j i d c 0 i z j z c z e z f z t y = i + t j i y c = e f i z j z c z d z e z f z i d y i = j c y d = e f a z b z c z d z t r y = a + t b a y = c + r d c b a d c 0 a z b z c z e z f z t y = a + t b a y c = e f a z b z c z d z e z f z a d y a = b c y d = e f
128 81 127 bitri i z j z k z l z o p y = i + o j i y = k + p l k j i l k 0 i z j z k z m z q z o y = i + o j i y k = m q i z j z k z l z m z q z i l y i = j k y l = m q a z b z c z d z t r y = a + t b a y = c + r d c b a d c 0 a z b z c z e z f z t y = a + t b a y c = e f a z b z c z d z e z f z a d y a = b c y d = e f
129 128 rabbii y | i z j z k z l z o p y = i + o j i y = k + p l k j i l k 0 i z j z k z m z q z o y = i + o j i y k = m q i z j z k z l z m z q z i l y i = j k y l = m q = y | a z b z c z d z t r y = a + t b a y = c + r d c b a d c 0 a z b z c z e z f z t y = a + t b a y c = e f a z b z c z d z e z f z a d y a = b c y d = e f
130 eqeq1 y = x y = a + t b a x = a + t b a
131 eqeq1 y = x y = c + r d c x = c + r d c
132 biidd y = x b a d c 0 b a d c 0
133 130 131 132 3anbi123d y = x y = a + t b a y = c + r d c b a d c 0 x = a + t b a x = c + r d c b a d c 0
134 133 2rexbidv y = x t r y = a + t b a y = c + r d c b a d c 0 t r x = a + t b a x = c + r d c b a d c 0
135 134 2rexbidv y = x c z d z t r y = a + t b a y = c + r d c b a d c 0 c z d z t r x = a + t b a x = c + r d c b a d c 0
136 135 2rexbidv y = x a z b z c z d z t r y = a + t b a y = c + r d c b a d c 0 a z b z c z d z t r x = a + t b a x = c + r d c b a d c 0
137 oveq1 y = x y c = x c
138 137 fveq2d y = x y c = x c
139 138 eqeq1d y = x y c = e f x c = e f
140 130 139 anbi12d y = x y = a + t b a y c = e f x = a + t b a x c = e f
141 140 2rexbidv y = x f z t y = a + t b a y c = e f f z t x = a + t b a x c = e f
142 141 2rexbidv y = x c z e z f z t y = a + t b a y c = e f c z e z f z t x = a + t b a x c = e f
143 142 2rexbidv y = x a z b z c z e z f z t y = a + t b a y c = e f a z b z c z e z f z t x = a + t b a x c = e f
144 biidd y = x a d a d
145 oveq1 y = x y a = x a
146 145 fveq2d y = x y a = x a
147 146 eqeq1d y = x y a = b c x a = b c
148 oveq1 y = x y d = x d
149 148 fveq2d y = x y d = x d
150 149 eqeq1d y = x y d = e f x d = e f
151 144 147 150 3anbi123d y = x a d y a = b c y d = e f a d x a = b c x d = e f
152 151 2rexbidv y = x e z f z a d y a = b c y d = e f e z f z a d x a = b c x d = e f
153 152 2rexbidv y = x c z d z e z f z a d y a = b c y d = e f c z d z e z f z a d x a = b c x d = e f
154 153 2rexbidv y = x a z b z c z d z e z f z a d y a = b c y d = e f a z b z c z d z e z f z a d x a = b c x d = e f
155 136 143 154 3orbi123d y = x a z b z c z d z t r y = a + t b a y = c + r d c b a d c 0 a z b z c z e z f z t y = a + t b a y c = e f a z b z c z d z e z f z a d y a = b c y d = e f a z b z c z d z t r x = a + t b a x = c + r d c b a d c 0 a z b z c z e z f z t x = a + t b a x c = e f a z b z c z d z e z f z a d x a = b c x d = e f
156 155 cbvrabv y | a z b z c z d z t r y = a + t b a y = c + r d c b a d c 0 a z b z c z e z f z t y = a + t b a y c = e f a z b z c z d z e z f z a d y a = b c y d = e f = x | a z b z c z d z t r x = a + t b a x = c + r d c b a d c 0 a z b z c z e z f z t x = a + t b a x c = e f a z b z c z d z e z f z a d x a = b c x d = e f
157 129 156 eqtri y | i z j z k z l z o p y = i + o j i y = k + p l k j i l k 0 i z j z k z m z q z o y = i + o j i y k = m q i z j z k z l z m z q z i l y i = j k y l = m q = x | a z b z c z d z t r x = a + t b a x = c + r d c b a d c 0 a z b z c z e z f z t x = a + t b a x c = e f a z b z c z d z e z f z a d x a = b c x d = e f
158 157 mpteq2i z V y | i z j z k z l z o p y = i + o j i y = k + p l k j i l k 0 i z j z k z m z q z o y = i + o j i y k = m q i z j z k z l z m z q z i l y i = j k y l = m q = z V x | a z b z c z d z t r x = a + t b a x = c + r d c b a d c 0 a z b z c z e z f z t x = a + t b a x c = e f a z b z c z d z e z f z a d x a = b c x d = e f
159 elequ2 z = s a z a s
160 elequ2 z = s b z b s
161 elequ2 z = s c z c s
162 rexeq z = s d z t r x = a + t b a x = c + r d c b a d c 0 d s t r x = a + t b a x = c + r d c b a d c 0
163 161 162 anbi12d z = s c z d z t r x = a + t b a x = c + r d c b a d c 0 c s d s t r x = a + t b a x = c + r d c b a d c 0
164 163 rexbidv2 z = s c z d z t r x = a + t b a x = c + r d c b a d c 0 c s d s t r x = a + t b a x = c + r d c b a d c 0
165 160 164 anbi12d z = s b z c z d z t r x = a + t b a x = c + r d c b a d c 0 b s c s d s t r x = a + t b a x = c + r d c b a d c 0
166 165 rexbidv2 z = s b z c z d z t r x = a + t b a x = c + r d c b a d c 0 b s c s d s t r x = a + t b a x = c + r d c b a d c 0
167 159 166 anbi12d z = s a z b z c z d z t r x = a + t b a x = c + r d c b a d c 0 a s b s c s d s t r x = a + t b a x = c + r d c b a d c 0
168 167 rexbidv2 z = s a z b z c z d z t r x = a + t b a x = c + r d c b a d c 0 a s b s c s d s t r x = a + t b a x = c + r d c b a d c 0
169 elequ2 z = s e z e s
170 rexeq z = s f z t x = a + t b a x c = e f f s t x = a + t b a x c = e f
171 169 170 anbi12d z = s e z f z t x = a + t b a x c = e f e s f s t x = a + t b a x c = e f
172 171 rexbidv2 z = s e z f z t x = a + t b a x c = e f e s f s t x = a + t b a x c = e f
173 161 172 anbi12d z = s c z e z f z t x = a + t b a x c = e f c s e s f s t x = a + t b a x c = e f
174 173 rexbidv2 z = s c z e z f z t x = a + t b a x c = e f c s e s f s t x = a + t b a x c = e f
175 160 174 anbi12d z = s b z c z e z f z t x = a + t b a x c = e f b s c s e s f s t x = a + t b a x c = e f
176 175 rexbidv2 z = s b z c z e z f z t x = a + t b a x c = e f b s c s e s f s t x = a + t b a x c = e f
177 159 176 anbi12d z = s a z b z c z e z f z t x = a + t b a x c = e f a s b s c s e s f s t x = a + t b a x c = e f
178 177 rexbidv2 z = s a z b z c z e z f z t x = a + t b a x c = e f a s b s c s e s f s t x = a + t b a x c = e f
179 elequ2 z = s d z d s
180 rexeq z = s f z a d x a = b c x d = e f f s a d x a = b c x d = e f
181 169 180 anbi12d z = s e z f z a d x a = b c x d = e f e s f s a d x a = b c x d = e f
182 181 rexbidv2 z = s e z f z a d x a = b c x d = e f e s f s a d x a = b c x d = e f
183 179 182 anbi12d z = s d z e z f z a d x a = b c x d = e f d s e s f s a d x a = b c x d = e f
184 183 rexbidv2 z = s d z e z f z a d x a = b c x d = e f d s e s f s a d x a = b c x d = e f
185 161 184 anbi12d z = s c z d z e z f z a d x a = b c x d = e f c s d s e s f s a d x a = b c x d = e f
186 185 rexbidv2 z = s c z d z e z f z a d x a = b c x d = e f c s d s e s f s a d x a = b c x d = e f
187 160 186 anbi12d z = s b z c z d z e z f z a d x a = b c x d = e f b s c s d s e s f s a d x a = b c x d = e f
188 187 rexbidv2 z = s b z c z d z e z f z a d x a = b c x d = e f b s c s d s e s f s a d x a = b c x d = e f
189 159 188 anbi12d z = s a z b z c z d z e z f z a d x a = b c x d = e f a s b s c s d s e s f s a d x a = b c x d = e f
190 189 rexbidv2 z = s a z b z c z d z e z f z a d x a = b c x d = e f a s b s c s d s e s f s a d x a = b c x d = e f
191 168 178 190 3orbi123d z = s a z b z c z d z t r x = a + t b a x = c + r d c b a d c 0 a z b z c z e z f z t x = a + t b a x c = e f a z b z c z d z e z f z a d x a = b c x d = e f a s b s c s d s t r x = a + t b a x = c + r d c b a d c 0 a s b s c s e s f s t x = a + t b a x c = e f a s b s c s d s e s f s a d x a = b c x d = e f
192 191 rabbidv z = s x | a z b z c z d z t r x = a + t b a x = c + r d c b a d c 0 a z b z c z e z f z t x = a + t b a x c = e f a z b z c z d z e z f z a d x a = b c x d = e f = x | a s b s c s d s t r x = a + t b a x = c + r d c b a d c 0 a s b s c s e s f s t x = a + t b a x c = e f a s b s c s d s e s f s a d x a = b c x d = e f
193 192 cbvmptv z V x | a z b z c z d z t r x = a + t b a x = c + r d c b a d c 0 a z b z c z e z f z t x = a + t b a x c = e f a z b z c z d z e z f z a d x a = b c x d = e f = s V x | a s b s c s d s t r x = a + t b a x = c + r d c b a d c 0 a s b s c s e s f s t x = a + t b a x c = e f a s b s c s d s e s f s a d x a = b c x d = e f
194 158 193 eqtri z V y | i z j z k z l z o p y = i + o j i y = k + p l k j i l k 0 i z j z k z m z q z o y = i + o j i y k = m q i z j z k z l z m z q z i l y i = j k y l = m q = s V x | a s b s c s d s t r x = a + t b a x = c + r d c b a d c 0 a s b s c s e s f s t x = a + t b a x c = e f a s b s c s d s e s f s a d x a = b c x d = e f
195 rdgeq1 z V y | i z j z k z l z o p y = i + o j i y = k + p l k j i l k 0 i z j z k z m z q z o y = i + o j i y k = m q i z j z k z l z m z q z i l y i = j k y l = m q = s V x | a s b s c s d s t r x = a + t b a x = c + r d c b a d c 0 a s b s c s e s f s t x = a + t b a x c = e f a s b s c s d s e s f s a d x a = b c x d = e f rec z V y | i z j z k z l z o p y = i + o j i y = k + p l k j i l k 0 i z j z k z m z q z o y = i + o j i y k = m q i z j z k z l z m z q z i l y i = j k y l = m q 0 1 = rec s V x | a s b s c s d s t r x = a + t b a x = c + r d c b a d c 0 a s b s c s e s f s t x = a + t b a x c = e f a s b s c s d s e s f s a d x a = b c x d = e f 0 1
196 194 195 ax-mp rec z V y | i z j z k z l z o p y = i + o j i y = k + p l k j i l k 0 i z j z k z m z q z o y = i + o j i y k = m q i z j z k z l z m z q z i l y i = j k y l = m q 0 1 = rec s V x | a s b s c s d s t r x = a + t b a x = c + r d c b a d c 0 a s b s c s e s f s t x = a + t b a x c = e f a s b s c s d s e s f s a d x a = b c x d = e f 0 1
197 eqid fld 𝑠 e = fld 𝑠 e
198 eqid fld 𝑠 f = fld 𝑠 f
199 oveq2 h = e fld 𝑠 h = fld 𝑠 e
200 199 adantl g = f h = e fld 𝑠 h = fld 𝑠 e
201 oveq2 g = f fld 𝑠 g = fld 𝑠 f
202 201 adantr g = f h = e fld 𝑠 g = fld 𝑠 f
203 200 202 breq12d g = f h = e fld 𝑠 h /FldExt fld 𝑠 g fld 𝑠 e /FldExt fld 𝑠 f
204 200 202 oveq12d g = f h = e fld 𝑠 h .:. fld 𝑠 g = fld 𝑠 e .:. fld 𝑠 f
205 204 eqeq1d g = f h = e fld 𝑠 h .:. fld 𝑠 g = 2 fld 𝑠 e .:. fld 𝑠 f = 2
206 203 205 anbi12d g = f h = e fld 𝑠 h /FldExt fld 𝑠 g fld 𝑠 h .:. fld 𝑠 g = 2 fld 𝑠 e /FldExt fld 𝑠 f fld 𝑠 e .:. fld 𝑠 f = 2
207 206 cbvopabv g h | fld 𝑠 h /FldExt fld 𝑠 g fld 𝑠 h .:. fld 𝑠 g = 2 = f e | fld 𝑠 e /FldExt fld 𝑠 f fld 𝑠 e .:. fld 𝑠 f = 2
208 peano1 ω
209 208 a1i φ ω
210 3 oveq2i fld 𝑠 S = fld 𝑠 fld fldGen A
211 2 210 eqtri L = fld 𝑠 fld fldGen A
212 196 197 198 207 209 1 211 4 constrext2chnlem φ n 0 L .:. Q = 2 n