Metamath Proof Explorer


Theorem stji1i

Description: Join of components of Sasaki arrow ->1. (Contributed by NM, 24-Oct-1999) (New usage is discouraged.)

Ref Expression
Hypotheses stle.1 A C
stle.2 B C
Assertion stji1i S States S A A B = S A + S A B

Proof

Step Hyp Ref Expression
1 stle.1 A C
2 stle.2 B C
3 1 choccli A C
4 1 2 chincli A B C
5 3 4 pm3.2i A C A B C
6 inss1 A B A
7 4 1 chsscon3i A B A A A B
8 6 7 mpbi A A B
9 stj S States A C A B C A A B S A A B = S A + S A B
10 5 8 9 mp2ani S States S A A B = S A + S A B