Nuprl Lemma : same-cubical-type-zero-and-one
∀[G:j⊢]. ∀[A,B:{G, 0(𝔽) ⊢ _}]. ∀[i:{G ⊢ _:𝕀}].  G, ((i=0) ∧ (i=1)) ⊢ A = B
Proof
Definitions occuring in Statement : 
same-cubical-type: Gamma ⊢ A = B, 
context-subset: Gamma, phi, 
face-zero: (i=0), 
face-one: (i=1), 
face-and: (a ∧ b), 
face-0: 0(𝔽), 
interval-type: 𝕀, 
cubical-term: {X ⊢ _:A}, 
cubical-type: {X ⊢ _}, 
cubical_set: CubicalSet, 
uall: ∀[x:A]. B[x]
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x], 
member: t ∈ T, 
same-cubical-type: Gamma ⊢ A = B, 
subtype_rel: A ⊆r B, 
uimplies: b supposing a, 
all: ∀x:A. B[x], 
implies: P ⇒ Q, 
squash: ↓T, 
prop: ℙ, 
true: True, 
cubical-type-at: A(a), 
pi1: fst(t), 
face-type: 𝔽, 
constant-cubical-type: (X), 
I_cube: A(I), 
functor-ob: ob(F), 
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, 
bdd-distributive-lattice: BoundedDistributiveLattice, 
so_lambda: λ2x.t[x], 
and: P ∧ Q, 
so_apply: x[s], 
guard: {T}, 
iff: P ⇐⇒ Q
Lemmas referenced : 
same-cubical-type-0, 
context-subset-subtype, 
face-0_wf, 
face-and_wf, 
face-zero_wf, 
face-one_wf, 
equal_wf, 
squash_wf, 
true_wf, 
istype-universe, 
lattice-point_wf, 
face_lattice_wf, 
cubical-term-at_wf, 
I_cube_wf, 
fset_wf, 
nat_wf, 
cubical-term_wf, 
cubical-type-cumulativity2, 
cubical_set_cumulativity-i-j, 
cubical-type_wf, 
cubical_set_wf, 
face-type_wf, 
face-zero-and-one, 
subtype_rel_self, 
subtype_rel_set, 
bounded-lattice-structure_wf, 
lattice-structure_wf, 
lattice-axioms_wf, 
bounded-lattice-structure-subtype, 
bounded-lattice-axioms_wf, 
lattice-meet_wf, 
lattice-join_wf, 
iff_weakening_equal, 
lattice-1_wf, 
interval-type_wf, 
context-subset_wf
Rules used in proof : 
cut, 
introduction, 
extract_by_obid, 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation_alt, 
hypothesis, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
applyEquality, 
independent_isectElimination, 
lambdaFormation_alt, 
lambdaEquality_alt, 
imageElimination, 
equalityTransitivity, 
equalitySymmetry, 
universeIsType, 
instantiate, 
universeEquality, 
because_Cache, 
sqequalRule, 
natural_numberEquality, 
imageMemberEquality, 
baseClosed, 
productEquality, 
cumulativity, 
isectEquality, 
productElimination, 
independent_functionElimination, 
equalityIstype, 
setElimination, 
rename, 
inhabitedIsType, 
axiomEquality
Latex:
\mforall{}[G:j\mvdash{}].  \mforall{}[A,B:\{G,  0(\mBbbF{})  \mvdash{}  \_\}].  \mforall{}[i:\{G  \mvdash{}  \_:\mBbbI{}\}].    G,  ((i=0)  \mwedge{}  (i=1))  \mvdash{}  A  =  B
Date html generated:
2020_05_20-PM-03_01_03
Last ObjectModification:
2020_04_06-AM-10_32_52
Theory : cubical!type!theory
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