Metamath Proof Explorer


Theorem pntrf

Description: Functionality of the residual. Lemma for pnt . (Contributed by Mario Carneiro, 8-Apr-2016)

Ref Expression
Hypothesis pntrval.r ⊢ R = a ∈ ℝ + ⟼ ψ ⁡ a − a
Assertion pntrf ⊢ R : ℝ + ⟶ ℝ

Proof

Step Hyp Ref Expression
1 pntrval.r ⊢ R = a ∈ ℝ + ⟼ ψ ⁡ a − a
2 rpre ⊢ a ∈ ℝ + → a ∈ ℝ
3 chpcl ⊢ a ∈ ℝ → ψ ⁡ a ∈ ℝ
4 2 3 syl ⊢ a ∈ ℝ + → ψ ⁡ a ∈ ℝ
5 4 2 resubcld ⊢ a ∈ ℝ + → ψ ⁡ a − a ∈ ℝ
6 1 5 fmpti ⊢ R : ℝ + ⟶ ℝ