Nuprl Lemma : discrete-map-is-constant2

∀[T:Type]. ∀[I:fset(ℕ)]. ∀[phi:𝔽(I)]. ∀[s:I,phi ⟶ discrete-cube(T)]. ∀[f:{f:I ⟶ I| (phi f) = 1} ].
  s = (λJ,g. (s I f)) ∈ I,phi ⟶ discrete-cube(T) 
  supposing ∀[J:fset(ℕ)]. ∀[g:J ⟶ I].  ((phi g) = 1 ⇒ (g = f ⋅ g ∈ J ⟶ I))


Proof




Definitions occuring in Statement :  cubical-subset: I,psi,  name-morph-satisfies: (psi f) = 1,  face-presheaf: 𝔽,  cube_set_map: A ⟶ B,  discrete-cube: discrete-cube(A),  I_cube: A(I),  nh-comp: g ⋅ f,  names-hom: I ⟶ J,  fset: fset(T),  nat: ℕ,  uimplies: b supposing a,  uall: ∀[x:A]. B[x],  implies: P ⇒ Q,  set: {x:A| B[x]} ,  apply: f a,  lambda: λx.A[x],  universe: Type,  equal: s = t ∈ T
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  uimplies: b supposing a,  cube_set_map: A ⟶ B,  cube-cat: CubeCat,  psc_map: A ⟶ B,  type-cat: TypeCat,  op-cat: op-cat(C),  nat-trans: nat-trans(C;D;F;G),  spreadn: spread4,  all: ∀x:A. B[x],  member: t ∈ T,  functor-arrow: arrow(F),  functor-ob: ob(F),  cubical-subset: I,psi,  discrete-cube: discrete-cube(A),  pi1: fst(t),  pi2: snd(t),  rep-sub-sheaf: rep-sub-sheaf(C;X;P),  cat-comp: cat-comp(C),  compose: f o g,  cat-arrow: cat-arrow(C),  implies: P ⇒ Q,  subtype_rel: A ⊆r B,  I_cube: A(I),  face-presheaf: 𝔽,  lattice-point: Point(l),  record-select: r.x,  face_lattice: face_lattice(I),  face-lattice: face-lattice(T;eq),  free-dist-lattice-with-constraints: free-dist-lattice-with-constraints(T;eq;x.Cs[x]),  constrained-antichain-lattice: constrained-antichain-lattice(T;eq;P),  mk-bounded-distributive-lattice: mk-bounded-distributive-lattice,  mk-bounded-lattice: mk-bounded-lattice(T;m;j;z;o),  record-update: r[x := v],  ifthenelse: if b then t else f fi ,  eq_atom: x =a y,  bfalse: ff,  btrue: tt,  prop: ℙ,  bdd-distributive-lattice: BoundedDistributiveLattice,  so_lambda: λ2x.t[x],  and: P ∧ Q,  so_apply: x[s],  squash: ↓T,  true: True,  guard: {T}
Lemmas referenced :  cat_arrow_triple_lemma,  cat_comp_tuple_lemma,  cat_ob_pair_lemma,  names-hom_wf,  name-morph-satisfies_wf,  subtype_rel_self,  lattice-point_wf,  face_lattice_wf,  nh-comp_wf,  subtype_rel_set,  bounded-lattice-structure_wf,  lattice-structure_wf,  lattice-axioms_wf,  bounded-lattice-structure-subtype,  bounded-lattice-axioms_wf,  equal_wf,  lattice-meet_wf,  lattice-join_wf,  cube_set_map_wf,  cubical-subset_wf,  discrete-cube_wf,  I_cube_wf,  face-presheaf_wf2,  fset_wf,  nat_wf,  istype-universe,  squash_wf,  true_wf,  implies-nh-comp-satisfies
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation_alt,  sqequalHypSubstitution,  sqequalRule,  cut,  introduction,  extract_by_obid,  dependent_functionElimination,  thin,  Error :memTop,  hypothesis,  setElimination,  rename,  dependent_set_memberEquality_alt,  isectIsType,  because_Cache,  universeIsType,  isectElimination,  hypothesisEquality,  functionIsType,  applyEquality,  equalityIstype,  setIsType,  instantiate,  lambdaEquality_alt,  productEquality,  cumulativity,  isectEquality,  independent_isectElimination,  universeEquality,  functionExtensionality,  applyLambdaEquality,  equalitySymmetry,  hyp_replacement,  imageElimination,  equalityTransitivity,  natural_numberEquality,  imageMemberEquality,  baseClosed,  setEquality,  independent_functionElimination,  lambdaFormation_alt,  inhabitedIsType

Latex:
\mforall{}[T:Type].  \mforall{}[I:fset(\mBbbN{})].  \mforall{}[phi:\mBbbF{}(I)].  \mforall{}[s:I,phi  {}\mrightarrow{}  discrete-cube(T)].  \mforall{}[f:\{f:I  {}\mrightarrow{}  I|  (phi  f)  =  1\}  ].
    s  =  (\mlambda{}J,g.  (s  I  f))  supposing  \mforall{}[J:fset(\mBbbN{})].  \mforall{}[g:J  {}\mrightarrow{}  I].    ((phi  g)  =  1  {}\mRightarrow{}  (g  =  f  \mcdot{}  g))



Date html generated: 2020_05_20-PM-02_32_05
Last ObjectModification: 2020_04_04-AM-09_47_48

Theory : cubical!type!theory


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