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Definition df-pm 7720
Description: Define the partial mapping operation. A partial function from 𝐵 to 𝐴 is a function from a subset of 𝐵 to 𝐴. The set of all partial functions from 𝐵 to 𝐴 is written (𝐴pm 𝐵) (see pmvalg 7728). A notation for this operation apparently does not appear in the literature. We use pm to distinguish it from the less general set exponentiation operation 𝑚 (df-map 7719) . See mapsspm 7750 for its relationship to set exponentiation. (Contributed by NM, 15-Nov-2007.)
Assertion
Ref Expression
df-pm pm = (𝑥 ∈ V, 𝑦 ∈ V ↦ {𝑓 ∈ 𝒫 (𝑦 × 𝑥) ∣ Fun 𝑓})
Distinct variable group:   𝑥,𝑦,𝑓

Detailed syntax breakdown of Definition df-pm
StepHypRef Expression
1 cpm 7718 . 2 class pm
2 vx . . 3 setvar 𝑥
3 vy . . 3 setvar 𝑦
4 cvv 3168 . . 3 class V
5 vf . . . . . 6 setvar 𝑓
65cv 1473 . . . . 5 class 𝑓
76wfun 5780 . . . 4 wff Fun 𝑓
83cv 1473 . . . . . 6 class 𝑦
92cv 1473 . . . . . 6 class 𝑥
108, 9cxp 5022 . . . . 5 class (𝑦 × 𝑥)
1110cpw 4103 . . . 4 class 𝒫 (𝑦 × 𝑥)
127, 5, 11crab 2895 . . 3 class {𝑓 ∈ 𝒫 (𝑦 × 𝑥) ∣ Fun 𝑓}
132, 3, 4, 4, 12cmpt2 6525 . 2 class (𝑥 ∈ V, 𝑦 ∈ V ↦ {𝑓 ∈ 𝒫 (𝑦 × 𝑥) ∣ Fun 𝑓})
141, 13wceq 1474 1 wff pm = (𝑥 ∈ V, 𝑦 ∈ V ↦ {𝑓 ∈ 𝒫 (𝑦 × 𝑥) ∣ Fun 𝑓})
Colors of variables: wff setvar class
This definition is referenced by:  fnpm  7725  pmvalg  7728
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