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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