Nuprl Lemma : mdist-symm

[X:Type]. ∀[d:metric(X)]. ∀[x,y:X].  (mdist(d;x;y) mdist(d;y;x))


Proof




Definitions occuring in Statement :  mdist: mdist(d;x;y) metric: metric(X) req: y uall: [x:A]. B[x] universe: Type
Definitions unfolded in proof :  mdist: mdist(d;x;y) uall: [x:A]. B[x] member: t ∈ T all: x:A. B[x] metric: metric(X) implies:  Q
Lemmas referenced :  metric-symmetry req_witness metric_wf istype-universe
Rules used in proof :  sqequalSubstitution sqequalRule sqequalReflexivity sqequalTransitivity computationStep isect_memberFormation_alt introduction cut extract_by_obid sqequalHypSubstitution isectElimination thin hypothesisEquality dependent_functionElimination hypothesis applyEquality setElimination rename because_Cache independent_functionElimination inhabitedIsType isect_memberEquality_alt isectIsTypeImplies universeIsType instantiate universeEquality

Latex:
\mforall{}[X:Type].  \mforall{}[d:metric(X)].  \mforall{}[x,y:X].    (mdist(d;x;y)  =  mdist(d;y;x))



Date html generated: 2019_10_29-AM-10_57_56
Last ObjectModification: 2019_10_02-AM-09_39_45

Theory : reals


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