Metamath Proof Explorer


Theorem stm1addi

Description: Sum of states whose meet is 1. (Contributed by NM, 11-Nov-1999) (New usage is discouraged.)

Ref Expression
Hypotheses stle.1 𝐴C
stle.2 𝐵C
Assertion stm1addi ( 𝑆 ∈ States → ( ( 𝑆 ‘ ( 𝐴𝐵 ) ) = 1 → ( ( 𝑆𝐴 ) + ( 𝑆𝐵 ) ) = 2 ) )

Proof

Step Hyp Ref Expression
1 stle.1 𝐴C
2 stle.2 𝐵C
3 1 2 stm1i ( 𝑆 ∈ States → ( ( 𝑆 ‘ ( 𝐴𝐵 ) ) = 1 → ( 𝑆𝐴 ) = 1 ) )
4 1 2 stm1ri ( 𝑆 ∈ States → ( ( 𝑆 ‘ ( 𝐴𝐵 ) ) = 1 → ( 𝑆𝐵 ) = 1 ) )
5 3 4 jcad ( 𝑆 ∈ States → ( ( 𝑆 ‘ ( 𝐴𝐵 ) ) = 1 → ( ( 𝑆𝐴 ) = 1 ∧ ( 𝑆𝐵 ) = 1 ) ) )
6 oveq12 ( ( ( 𝑆𝐴 ) = 1 ∧ ( 𝑆𝐵 ) = 1 ) → ( ( 𝑆𝐴 ) + ( 𝑆𝐵 ) ) = ( 1 + 1 ) )
7 df-2 2 = ( 1 + 1 )
8 6 7 eqtr4di ( ( ( 𝑆𝐴 ) = 1 ∧ ( 𝑆𝐵 ) = 1 ) → ( ( 𝑆𝐴 ) + ( 𝑆𝐵 ) ) = 2 )
9 5 8 syl6 ( 𝑆 ∈ States → ( ( 𝑆 ‘ ( 𝐴𝐵 ) ) = 1 → ( ( 𝑆𝐴 ) + ( 𝑆𝐵 ) ) = 2 ) )