Description: The value of a function with a domain of two elements. (Contributed by Jeff Madsen, 20-Jun-2010) (Proof shortened by BJ, 26-Sep-2024)
Ref | Expression | ||
---|---|---|---|
Hypotheses | fvpr2.1 | ⊢ 𝐵 ∈ V | |
fvpr2.2 | ⊢ 𝐷 ∈ V | ||
Assertion | fvpr2 | ⊢ ( 𝐴 ≠ 𝐵 → ( { 〈 𝐴 , 𝐶 〉 , 〈 𝐵 , 𝐷 〉 } ‘ 𝐵 ) = 𝐷 ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | fvpr2.1 | ⊢ 𝐵 ∈ V | |
2 | fvpr2.2 | ⊢ 𝐷 ∈ V | |
3 | fvpr2g | ⊢ ( ( 𝐵 ∈ V ∧ 𝐷 ∈ V ∧ 𝐴 ≠ 𝐵 ) → ( { 〈 𝐴 , 𝐶 〉 , 〈 𝐵 , 𝐷 〉 } ‘ 𝐵 ) = 𝐷 ) | |
4 | 1 2 3 | mp3an12 | ⊢ ( 𝐴 ≠ 𝐵 → ( { 〈 𝐴 , 𝐶 〉 , 〈 𝐵 , 𝐷 〉 } ‘ 𝐵 ) = 𝐷 ) |