Nuprl Lemma : case-term-same
∀[Gamma:j⊢]. ∀[phi:{Gamma ⊢ _:𝔽}]. ∀[A:{Gamma, phi ⊢ _}]. ∀[u:{Gamma, phi ⊢ _:A}].  ((u ∨ u) = u ∈ {Gamma, phi ⊢ _:A})
Proof
Definitions occuring in Statement : 
case-term: (u ∨ v), 
context-subset: Gamma, phi, 
face-type: 𝔽, 
cubical-term: {X ⊢ _:A}, 
cubical-type: {X ⊢ _}, 
cubical_set: CubicalSet, 
uall: ∀[x:A]. B[x], 
equal: s = t ∈ T
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x], 
case-term: (u ∨ v), 
cubical-term-at: u(a), 
member: t ∈ T, 
subtype_rel: A ⊆r B, 
uimplies: b supposing a, 
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], 
prop: ℙ, 
and: P ∧ Q, 
so_apply: x[s], 
all: ∀x:A. B[x], 
implies: P ⇒ Q, 
bool: 𝔹, 
unit: Unit, 
it: ⋅, 
uiff: uiff(P;Q), 
exists: ∃x:A. B[x], 
or: P ∨ Q, 
sq_type: SQType(T), 
guard: {T}, 
bnot: ¬bb, 
assert: ↑b, 
false: False, 
not: ¬A, 
rev_implies: P ⇐ Q, 
iff: P ⇐⇒ Q
Lemmas referenced : 
fl-eq_wf, 
cubical-term-at_wf, 
context-subset_wf, 
face-type_wf, 
subset-cubical-term, 
context-subset-is-subset, 
subtype_rel_self, 
lattice-point_wf, 
face_lattice_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, 
lattice-1_wf, 
eqtt_to_assert, 
assert-fl-eq, 
eqff_to_assert, 
bool_cases_sqequal, 
subtype_base_sq, 
bool_wf, 
bool_subtype_base, 
assert-bnot, 
iff_weakening_uiff, 
assert_wf, 
I_cube_wf, 
fset_wf, 
nat_wf, 
cubical-term-equal, 
cubical-term_wf, 
cubical-type-cumulativity2, 
cubical_set_cumulativity-i-j, 
cubical-type_wf, 
cubical_set_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation_alt, 
equalitySymmetry, 
cut, 
functionExtensionality, 
sqequalRule, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
hypothesis, 
applyEquality, 
independent_isectElimination, 
because_Cache, 
instantiate, 
lambdaEquality_alt, 
productEquality, 
cumulativity, 
isectEquality, 
universeIsType, 
setElimination, 
rename, 
inhabitedIsType, 
equalityTransitivity, 
lambdaFormation_alt, 
unionElimination, 
equalityElimination, 
productElimination, 
dependent_pairFormation_alt, 
equalityIstype, 
promote_hyp, 
dependent_functionElimination, 
independent_functionElimination, 
voidElimination
Latex:
\mforall{}[Gamma:j\mvdash{}].  \mforall{}[phi:\{Gamma  \mvdash{}  \_:\mBbbF{}\}].  \mforall{}[A:\{Gamma,  phi  \mvdash{}  \_\}].  \mforall{}[u:\{Gamma,  phi  \mvdash{}  \_:A\}].    ((u  \mvee{}  u)  =  u)
Date html generated:
2020_05_20-PM-03_10_40
Last ObjectModification:
2020_04_06-PM-00_53_28
Theory : cubical!type!theory
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