Nuprl Lemma : image-metric_wf

[X,Y:Type]. ∀[f:X ⟶ Y]. ∀[d:metric(Y)].  (image-metric(d) ∈ metric(f[X]))


Proof




Definitions occuring in Statement :  image-metric: image-metric(d) image-space: f[X] metric: metric(X) uall: [x:A]. B[x] member: t ∈ T function: x:A ⟶ B[x] universe: Type
Definitions unfolded in proof :  prop: mdist: mdist(d;x;y) pi1: fst(t) all: x:A. B[x] cand: c∧ B and: P ∧ Q top: Top image-space: f[X] metric: metric(X) image-metric: image-metric(d) member: t ∈ T uall: [x:A]. B[x]
Lemmas referenced :  istype-universe metric_wf int-to-real_wf req_wf radd_wf rleq_wf mdist-same mdist-triangle-inequality1 image-space_wf istype-void pi1_wf_top
Rules used in proof :  universeEquality instantiate isectIsTypeImplies axiomEquality natural_numberEquality functionIsType productIsType because_Cache equalityElimination independent_pairFormation lambdaFormation_alt equalitySymmetry equalityTransitivity dependent_set_memberEquality_alt universeIsType inhabitedIsType voidElimination isect_memberEquality_alt independent_pairEquality productElimination isectElimination extract_by_obid hypothesis hypothesisEquality rename thin setElimination sqequalHypSubstitution applyEquality lambdaEquality_alt sqequalRule cut introduction isect_memberFormation_alt sqequalReflexivity computationStep sqequalTransitivity sqequalSubstitution

Latex:
\mforall{}[X,Y:Type].  \mforall{}[f:X  {}\mrightarrow{}  Y].  \mforall{}[d:metric(Y)].    (image-metric(d)  \mmember{}  metric(f[X]))



Date html generated: 2019_10_30-AM-06_35_27
Last ObjectModification: 2019_10_25-AM-11_11_40

Theory : reals


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