Metamath Proof Explorer


Theorem sdomentr

Description: Transitivity of strict dominance and equinumerosity. Exercise 11 of Suppes p. 98. (Contributed by NM, 26-Oct-2003)

Ref Expression
Assertion sdomentr ( ( 𝐴 ≺ 𝐵 ∧ 𝐵 ≈ 𝐶 ) → 𝐴 ≺ 𝐶 )

Proof

Step Hyp Ref Expression
1 endom ⊢ ( 𝐵 ≈ 𝐶 → 𝐵 ≼ 𝐶 )
2 sdomdomtr ⊢ ( ( 𝐴 ≺ 𝐵 ∧ 𝐵 ≼ 𝐶 ) → 𝐴 ≺ 𝐶 )
3 1 2 sylan2 ⊢ ( ( 𝐴 ≺ 𝐵 ∧ 𝐵 ≈ 𝐶 ) → 𝐴 ≺ 𝐶 )