Nuprl Lemma : discrete-path-endpoints
∀[X:j⊢]. ∀[T:Type].
  ∀a:{X ⊢ _:discr(T)}. ∀[b:{X ⊢ _:discr(T)}]. ∀[p:{X ⊢ _:(Path_discr(T) a b)}].  (a = b ∈ {X ⊢ _:discr(T)})
Proof
Definitions occuring in Statement : 
path-type: (Path_A a b)
, 
discrete-cubical-type: discr(T)
, 
cubical-term: {X ⊢ _:A}
, 
cubical_set: CubicalSet
, 
uall: ∀[x:A]. B[x]
, 
all: ∀x:A. B[x]
, 
universe: Type
, 
equal: s = t ∈ T
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
all: ∀x:A. B[x]
, 
subtype_rel: A ⊆r B
, 
implies: P 
⇒ Q
, 
uimplies: b supposing a
, 
discrete-cubical-type: discr(T)
, 
cubical-term-at: u(a)
, 
cubical-term: {X ⊢ _:A}
, 
interval-type: 𝕀
, 
cube-context-adjoin: X.A
, 
cubical-type-at: A(a)
, 
interval-presheaf: 𝕀
, 
constant-cubical-type: (X)
, 
pi1: fst(t)
, 
interval-1: 1(𝕀)
, 
csm-id-adjoin: [u]
, 
csm-ap: (s)x
, 
interval-0: 0(𝕀)
, 
csm-id: 1(X)
, 
csm-adjoin: (s;u)
, 
nat: ℕ
, 
le: A ≤ B
, 
and: P ∧ Q
, 
less_than': less_than'(a;b)
, 
not: ¬A
, 
false: False
, 
names-hom: I ⟶ J
, 
so_lambda: λ2x.t[x]
, 
so_apply: x[s]
, 
uiff: uiff(P;Q)
, 
names: names(I)
, 
prop: ℙ
, 
squash: ↓T
, 
DeMorgan-algebra: DeMorganAlgebra
, 
guard: {T}
, 
true: True
, 
iff: P 
⇐⇒ Q
, 
rev_implies: P 
⇐ Q
, 
pi2: snd(t)
, 
cubical-path-app: pth @ r
Lemmas referenced : 
path-eta_wf, 
discrete-cubical-type_wf, 
path-type-subtype, 
csm-discrete-cubical-type, 
cubical-term_wf, 
path-type_wf, 
cubical-type-cumulativity2, 
cubical_set_cumulativity-i-j, 
istype-universe, 
cubical_set_wf, 
I_cube_wf, 
fset_wf, 
nat_wf, 
cubical-term-equal, 
csm-ap-term_wf, 
cube-context-adjoin_wf, 
interval-type_wf, 
csm-id-adjoin_wf-interval-0, 
subset-cubical-term2, 
sub_cubical_set_self, 
csm-ap-type_wf, 
cubical_type_at_pair_lemma, 
csm-ap-term-at, 
I_cube_pair_redex_lemma, 
cube_set_restriction_pair_lemma, 
cubical_type_ap_morph_pair_lemma, 
istype-void, 
istype-le, 
fset-singleton_wf, 
dM_inc_wf, 
member-fset-singleton, 
int-deq_wf, 
strong-subtype-deq-subtype, 
strong-subtype-set3, 
le_wf, 
istype-int, 
strong-subtype-self, 
fset-member_wf, 
names_wf, 
equal_wf, 
squash_wf, 
true_wf, 
dM0_wf, 
lattice-point_wf, 
dM_wf, 
subtype_rel_set, 
DeMorgan-algebra-structure_wf, 
lattice-structure_wf, 
lattice-axioms_wf, 
bounded-lattice-structure-subtype, 
DeMorgan-algebra-structure-subtype, 
subtype_rel_transitivity, 
bounded-lattice-structure_wf, 
bounded-lattice-axioms_wf, 
lattice-meet_wf, 
lattice-join_wf, 
DeMorgan-algebra-axioms_wf, 
dM1_wf, 
subtype_rel_self, 
iff_weakening_equal, 
cube-set-restriction_wf, 
dM-lift-0, 
dM-lift-1, 
names-hom_wf, 
dM-lift-inc, 
cubical-path-app-0, 
cubical-path-app-1, 
path-eta-0, 
path-eta-1
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation_alt, 
introduction, 
cut, 
lambdaFormation_alt, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
hypothesis, 
applyEquality, 
because_Cache, 
sqequalRule, 
Error :memTop, 
universeIsType, 
instantiate, 
isect_memberEquality_alt, 
axiomEquality, 
isectIsTypeImplies, 
inhabitedIsType, 
cumulativity, 
lambdaEquality_alt, 
dependent_functionElimination, 
functionIsTypeImplies, 
universeEquality, 
equalityTransitivity, 
equalitySymmetry, 
equalityIstype, 
independent_functionElimination, 
functionExtensionality, 
independent_isectElimination, 
setElimination, 
rename, 
dependent_set_memberEquality_alt, 
natural_numberEquality, 
independent_pairFormation, 
voidElimination, 
intEquality, 
productElimination, 
imageElimination, 
dependent_pairEquality_alt, 
productEquality, 
isectEquality, 
imageMemberEquality, 
baseClosed, 
hyp_replacement
Latex:
\mforall{}[X:j\mvdash{}].  \mforall{}[T:Type].
    \mforall{}a:\{X  \mvdash{}  \_:discr(T)\}.  \mforall{}[b:\{X  \mvdash{}  \_:discr(T)\}].  \mforall{}[p:\{X  \mvdash{}  \_:(Path\_discr(T)  a  b)\}].    (a  =  b)
Date html generated:
2020_05_20-PM-03_36_05
Last ObjectModification:
2020_04_08-PM-09_54_51
Theory : cubical!type!theory
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