Database
ZF (ZERMELO-FRAENKEL) SET THEORY
ZF Set Theory - add the Axiom of Power Sets
Operations
df-mpo
Metamath Proof Explorer
Description: Define maps-to notation for defining an operation via a rule. Read as
"the operation defined by the map from x , y (in A X. B ) to
C ( x , y ) ". An extension of df-mpt for two arguments.
(Contributed by NM , 17-Feb-2008)
Ref
Expression
Assertion
df-mpo
⊢ x ∈ A , y ∈ B ⟼ C = x y z | x ∈ A ∧ y ∈ B ∧ z = C
Detailed syntax breakdown
Step
Hyp
Ref
Expression
0
vx
setvar x
1
cA
class A
2
vy
setvar y
3
cB
class B
4
cC
class C
5
0 2 1 3 4
cmpo
class x ∈ A , y ∈ B ⟼ C
6
vz
setvar z
7
0
cv
setvar x
8
7 1
wcel
wff x ∈ A
9
2
cv
setvar y
10
9 3
wcel
wff y ∈ B
11
8 10
wa
wff x ∈ A ∧ y ∈ B
12
6
cv
setvar z
13
12 4
wceq
wff z = C
14
11 13
wa
wff x ∈ A ∧ y ∈ B ∧ z = C
15
14 0 2 6
coprab
class x y z | x ∈ A ∧ y ∈ B ∧ z = C
16
5 15
wceq
wff x ∈ A , y ∈ B ⟼ C = x y z | x ∈ A ∧ y ∈ B ∧ z = C