Metamath Proof Explorer


Theorem btwnexch3

Description: Exchange the first endpoint in betweenness. Left-hand side of Theorem 3.6 of Schwabhauser p. 30. (Contributed by Scott Fenton, 12-Jun-2013)

Ref Expression
Assertion btwnexch3 N A 𝔼 N B 𝔼 N C 𝔼 N D 𝔼 N B Btwn A C C Btwn A D C Btwn B D

Proof

Step Hyp Ref Expression
1 simp1 N A 𝔼 N B 𝔼 N C 𝔼 N D 𝔼 N N
2 simp3l N A 𝔼 N B 𝔼 N C 𝔼 N D 𝔼 N C 𝔼 N
3 simp2l N A 𝔼 N B 𝔼 N C 𝔼 N D 𝔼 N A 𝔼 N
4 simp3r N A 𝔼 N B 𝔼 N C 𝔼 N D 𝔼 N D 𝔼 N
5 btwncom N C 𝔼 N A 𝔼 N D 𝔼 N C Btwn A D C Btwn D A
6 1 2 3 4 5 syl13anc N A 𝔼 N B 𝔼 N C 𝔼 N D 𝔼 N C Btwn A D C Btwn D A
7 simp2r N A 𝔼 N B 𝔼 N C 𝔼 N D 𝔼 N B 𝔼 N
8 btwncom N B 𝔼 N A 𝔼 N C 𝔼 N B Btwn A C B Btwn C A
9 1 7 3 2 8 syl13anc N A 𝔼 N B 𝔼 N C 𝔼 N D 𝔼 N B Btwn A C B Btwn C A
10 6 9 anbi12d N A 𝔼 N B 𝔼 N C 𝔼 N D 𝔼 N C Btwn A D B Btwn A C C Btwn D A B Btwn C A
11 axpasch N D 𝔼 N C 𝔼 N A 𝔼 N C 𝔼 N B 𝔼 N C Btwn D A B Btwn C A x 𝔼 N x Btwn C C x Btwn B D
12 1 4 2 3 2 7 11 syl132anc N A 𝔼 N B 𝔼 N C 𝔼 N D 𝔼 N C Btwn D A B Btwn C A x 𝔼 N x Btwn C C x Btwn B D
13 10 12 sylbid N A 𝔼 N B 𝔼 N C 𝔼 N D 𝔼 N C Btwn A D B Btwn A C x 𝔼 N x Btwn C C x Btwn B D
14 13 ancomsd N A 𝔼 N B 𝔼 N C 𝔼 N D 𝔼 N B Btwn A C C Btwn A D x 𝔼 N x Btwn C C x Btwn B D
15 simpl1 N A 𝔼 N B 𝔼 N C 𝔼 N D 𝔼 N x 𝔼 N N
16 simpr N A 𝔼 N B 𝔼 N C 𝔼 N D 𝔼 N x 𝔼 N x 𝔼 N
17 simpl3l N A 𝔼 N B 𝔼 N C 𝔼 N D 𝔼 N x 𝔼 N C 𝔼 N
18 axbtwnid N x 𝔼 N C 𝔼 N x Btwn C C x = C
19 15 16 17 18 syl3anc N A 𝔼 N B 𝔼 N C 𝔼 N D 𝔼 N x 𝔼 N x Btwn C C x = C
20 breq1 x = C x Btwn B D C Btwn B D
21 20 biimpd x = C x Btwn B D C Btwn B D
22 19 21 syl6 N A 𝔼 N B 𝔼 N C 𝔼 N D 𝔼 N x 𝔼 N x Btwn C C x Btwn B D C Btwn B D
23 22 impd N A 𝔼 N B 𝔼 N C 𝔼 N D 𝔼 N x 𝔼 N x Btwn C C x Btwn B D C Btwn B D
24 23 rexlimdva N A 𝔼 N B 𝔼 N C 𝔼 N D 𝔼 N x 𝔼 N x Btwn C C x Btwn B D C Btwn B D
25 14 24 syld N A 𝔼 N B 𝔼 N C 𝔼 N D 𝔼 N B Btwn A C C Btwn A D C Btwn B D