Metamath Proof Explorer


Theorem stm1i

Description: State of component of unit meet. (Contributed by NM, 11-Nov-1999) (New usage is discouraged.)

Ref Expression
Hypotheses stle.1 𝐴C
stle.2 𝐵C
Assertion stm1i ( 𝑆 ∈ States → ( ( 𝑆 ‘ ( 𝐴𝐵 ) ) = 1 → ( 𝑆𝐴 ) = 1 ) )

Proof

Step Hyp Ref Expression
1 stle.1 𝐴C
2 stle.2 𝐵C
3 inss1 ( 𝐴𝐵 ) ⊆ 𝐴
4 1 2 chincli ( 𝐴𝐵 ) ∈ C
5 4 1 stlei ( 𝑆 ∈ States → ( ( 𝐴𝐵 ) ⊆ 𝐴 → ( 𝑆 ‘ ( 𝐴𝐵 ) ) ≤ ( 𝑆𝐴 ) ) )
6 3 5 mpi ( 𝑆 ∈ States → ( 𝑆 ‘ ( 𝐴𝐵 ) ) ≤ ( 𝑆𝐴 ) )
7 breq1 ( ( 𝑆 ‘ ( 𝐴𝐵 ) ) = 1 → ( ( 𝑆 ‘ ( 𝐴𝐵 ) ) ≤ ( 𝑆𝐴 ) ↔ 1 ≤ ( 𝑆𝐴 ) ) )
8 6 7 syl5ibcom ( 𝑆 ∈ States → ( ( 𝑆 ‘ ( 𝐴𝐵 ) ) = 1 → 1 ≤ ( 𝑆𝐴 ) ) )
9 1 stge1i ( 𝑆 ∈ States → ( 1 ≤ ( 𝑆𝐴 ) ↔ ( 𝑆𝐴 ) = 1 ) )
10 8 9 sylibd ( 𝑆 ∈ States → ( ( 𝑆 ‘ ( 𝐴𝐵 ) ) = 1 → ( 𝑆𝐴 ) = 1 ) )