Description: In dimension 2 and above, on a line ( A L B ) there is always a perpendicular P from A on a given plane (here given by C , in case C does not lie on the line). Theorem 8.21 of Schwabhauser p. 63. (Contributed by Thierry Arnoux, 20-Nov-2019)
Ref | Expression | ||
---|---|---|---|
Hypotheses | colperpex.p | |
|
colperpex.d | |
||
colperpex.i | |
||
colperpex.l | |
||
colperpex.g | |
||
colperpex.1 | |
||
colperpex.2 | |
||
colperpex.3 | |
||
colperpex.4 | |
||
colperpex.5 | |
||
Assertion | colperpex | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | colperpex.p | |
|
2 | colperpex.d | |
|
3 | colperpex.i | |
|
4 | colperpex.l | |
|
5 | colperpex.g | |
|
6 | colperpex.1 | |
|
7 | colperpex.2 | |
|
8 | colperpex.3 | |
|
9 | colperpex.4 | |
|
10 | colperpex.5 | |
|
11 | 5 | ad3antrrr | |
12 | 6 | ad3antrrr | |
13 | 7 | ad3antrrr | |
14 | simplr | |
|
15 | 9 | ad3antrrr | |
16 | simpr | |
|
17 | 1 2 3 4 11 12 13 14 15 16 | colperpexlem3 | |
18 | simprl | |
|
19 | 8 | ad5antr | |
20 | simp-5r | |
|
21 | 20 | orcd | |
22 | 5 | ad5antr | |
23 | simplr | |
|
24 | 1 2 3 22 19 23 | tgbtwntriv1 | |
25 | eleq1 | |
|
26 | 25 | orbi1d | |
27 | eleq1 | |
|
28 | 26 27 | anbi12d | |
29 | 28 | rspcev | |
30 | 19 21 24 29 | syl12anc | |
31 | 18 30 | jca | |
32 | 31 | ex | |
33 | 32 | reximdva | |
34 | 17 33 | mpd | |
35 | 5 | adantr | |
36 | 10 | adantr | |
37 | 6 | adantr | |
38 | 7 | adantr | |
39 | 9 | adantr | |
40 | 1 3 4 35 36 37 38 39 | tglowdim2ln | |
41 | 34 40 | r19.29a | |
42 | 5 | adantr | |
43 | 6 | adantr | |
44 | 7 | adantr | |
45 | 8 | adantr | |
46 | 9 | adantr | |
47 | simpr | |
|
48 | 1 2 3 4 42 43 44 45 46 47 | colperpexlem3 | |
49 | 41 48 | pm2.61dan | |