Metamath Proof Explorer


Theorem curry2val

Description: The value of a curried function with a constant second argument. (Contributed by NM, 16-Dec-2008)

Ref Expression
Hypothesis curry2.1 ⊢ G = F ∘ 1 st ↾ V × C -1
Assertion curry2val ⊢ F Fn A × B ∧ C ∈ B → G ⁡ D = D F C

Proof

Step Hyp Ref Expression
1 curry2.1 ⊢ G = F ∘ 1 st ↾ V × C -1
2 1 curry2 ⊢ F Fn A × B ∧ C ∈ B → G = x ∈ A ⟼ x F C
3 2 fveq1d ⊢ F Fn A × B ∧ C ∈ B → G ⁡ D = x ∈ A ⟼ x F C ⁡ D
4 eqid ⊢ x ∈ A ⟼ x F C = x ∈ A ⟼ x F C
5 4 fvmptndm ⊢ ¬ D ∈ A → x ∈ A ⟼ x F C ⁡ D = ∅
6 5 adantl ⊢ F Fn A × B ∧ ¬ D ∈ A → x ∈ A ⟼ x F C ⁡ D = ∅
7 fndm ⊢ F Fn A × B → dom ⁡ F = A × B
8 simpl ⊢ D ∈ A ∧ C ∈ B → D ∈ A
9 8 con3i ⊢ ¬ D ∈ A → ¬ D ∈ A ∧ C ∈ B
10 ndmovg ⊢ dom ⁡ F = A × B ∧ ¬ D ∈ A ∧ C ∈ B → D F C = ∅
11 7 9 10 syl2an ⊢ F Fn A × B ∧ ¬ D ∈ A → D F C = ∅
12 6 11 eqtr4d ⊢ F Fn A × B ∧ ¬ D ∈ A → x ∈ A ⟼ x F C ⁡ D = D F C
13 12 ex ⊢ F Fn A × B → ¬ D ∈ A → x ∈ A ⟼ x F C ⁡ D = D F C
14 13 adantr ⊢ F Fn A × B ∧ C ∈ B → ¬ D ∈ A → x ∈ A ⟼ x F C ⁡ D = D F C
15 oveq1 ⊢ x = D → x F C = D F C
16 ovex ⊢ D F C ∈ V
17 15 4 16 fvmpt ⊢ D ∈ A → x ∈ A ⟼ x F C ⁡ D = D F C
18 14 17 pm2.61d2 ⊢ F Fn A × B ∧ C ∈ B → x ∈ A ⟼ x F C ⁡ D = D F C
19 3 18 eqtrd ⊢ F Fn A × B ∧ C ∈ B → G ⁡ D = D F C