Nuprl Lemma : cubes-arrow

[X:Top]. (cat-arrow(cubes(X)) ~ λAa,Bb. let A,a Aa in let B,b Bb in {f:A ⟶ B| f(b) a ∈ (X A)} )


Proof




Definitions occuring in Statement :  cubes: cubes(X) cube-set-restriction: f(s) names-hom: I ⟶ J functor-ob: ob(F) cat-arrow: cat-arrow(C) uall: [x:A]. B[x] top: Top set: {x:A| B[x]}  apply: a lambda: λx.A[x] spread: spread def sqequal: t equal: t ∈ T
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T cubes: cubes(X) cube-cat: CubeCat all: x:A. B[x] top: Top cube-set-restriction: f(s) psc-restriction: f(s)
Lemmas referenced :  sets-arrow cube-cat_wf cat_arrow_triple_lemma
Rules used in proof :  cut introduction extract_by_obid sqequalHypSubstitution sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isectElimination thin hypothesis sqequalRule dependent_functionElimination isect_memberEquality voidElimination voidEquality

Latex:
\mforall{}[X:Top].  (cat-arrow(cubes(X))  \msim{}  \mlambda{}Aa,Bb.  let  A,a  =  Aa  in  let  B,b  =  Bb  in  \{f:A  {}\mrightarrow{}  B|  f(b)  =  a\}  )



Date html generated: 2018_05_23-AM-08_33_24
Last ObjectModification: 2018_05_20-PM-05_46_27

Theory : cubical!type!theory


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