Metamath Proof Explorer


Theorem strle2

Description: Make a structure from a pair. (Contributed by Mario Carneiro, 29-Aug-2015)

Ref Expression
Hypotheses strle1.i 𝐼 ∈ ℕ
strle1.a 𝐴 = 𝐼
strle2.j 𝐼 < 𝐽
strle2.k 𝐽 ∈ ℕ
strle2.b 𝐵 = 𝐽
Assertion strle2 { ⟨ 𝐴 , 𝑋 ⟩ , ⟨ 𝐵 , 𝑌 ⟩ } Struct ⟨ 𝐼 , 𝐽

Proof

Step Hyp Ref Expression
1 strle1.i 𝐼 ∈ ℕ
2 strle1.a 𝐴 = 𝐼
3 strle2.j 𝐼 < 𝐽
4 strle2.k 𝐽 ∈ ℕ
5 strle2.b 𝐵 = 𝐽
6 df-pr { ⟨ 𝐴 , 𝑋 ⟩ , ⟨ 𝐵 , 𝑌 ⟩ } = ( { ⟨ 𝐴 , 𝑋 ⟩ } ∪ { ⟨ 𝐵 , 𝑌 ⟩ } )
7 1 2 strle1 { ⟨ 𝐴 , 𝑋 ⟩ } Struct ⟨ 𝐼 , 𝐼
8 4 5 strle1 { ⟨ 𝐵 , 𝑌 ⟩ } Struct ⟨ 𝐽 , 𝐽
9 7 8 3 strleun ( { ⟨ 𝐴 , 𝑋 ⟩ } ∪ { ⟨ 𝐵 , 𝑌 ⟩ } ) Struct ⟨ 𝐼 , 𝐽
10 6 9 eqbrtri { ⟨ 𝐴 , 𝑋 ⟩ , ⟨ 𝐵 , 𝑌 ⟩ } Struct ⟨ 𝐼 , 𝐽