Nuprl Lemma : sets-arrow

∀[C:SmallCategory]. ∀[X:Top].
  (cat-arrow(sets(C; X)) ~ λAa,Bb. let A,a = Aa in let B,b = Bb in {f:cat-arrow(C) A B| f(b) = a ∈ (X A)} )


Proof




Definitions occuring in Statement :  sets: sets(C; X),  psc-restriction: f(s),  functor-ob: ob(F),  cat-arrow: cat-arrow(C),  small-category: SmallCategory,  uall: ∀[x:A]. B[x],  top: Top,  set: {x:A| B[x]} ,  apply: f a,  lambda: λx.A[x],  spread: spread def,  sqequal: s ~ t,  equal: s = t ∈ T
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  small-category: SmallCategory,  spreadn: spread4,  psc-restriction: f(s),  sets: sets(C; X),  all: ∀x:A. B[x],  top: Top,  presheaf-elements: el(P),  mk-cat: mk-cat,  and: P ∧ Q,  functor-arrow: arrow(F),  pi2: snd(t)
Lemmas referenced :  cat_arrow_triple_lemma,  op-cat-arrow,  top_wf,  small-category_wf
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  introduction,  cut,  hypothesisEquality,  sqequalHypSubstitution,  setElimination,  thin,  rename,  productElimination,  sqequalRule,  extract_by_obid,  dependent_functionElimination,  isect_memberEquality,  voidElimination,  voidEquality,  hypothesis,  equalityTransitivity,  equalitySymmetry,  isectElimination,  sqequalAxiom,  because_Cache

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



Date html generated: 2018_05_22-PM-09_59_17
Last ObjectModification: 2018_05_20-PM-09_42_07

Theory : presheaf!models!of!type!theory


Home Index