Nuprl Lemma : context-iterated-subset
∀[Gamma:j⊢]. ∀[phi,psi:{Gamma ⊢ _:𝔽}].
  (sub_cubical_set{j:l}(Gamma, (phi ∧ psi); Gamma, psi, phi)
  ∧ sub_cubical_set{j:l}(Gamma, psi, phi; Gamma, (phi ∧ psi)))
Proof
Definitions occuring in Statement : 
context-subset: Gamma, phi
, 
face-and: (a ∧ b)
, 
face-type: 𝔽
, 
cubical-term: {X ⊢ _:A}
, 
sub_cubical_set: Y ⊆ X
, 
cubical_set: CubicalSet
, 
uall: ∀[x:A]. B[x]
, 
and: P ∧ Q
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
and: P ∧ Q
, 
cand: A c∧ B
, 
subtype_rel: A ⊆r B
, 
uimplies: b supposing a
, 
all: ∀x:A. B[x]
, 
context-subset: Gamma, phi
, 
iff: P 
⇐⇒ Q
, 
implies: P 
⇒ Q
, 
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
, 
so_apply: x[s]
, 
squash: ↓T
, 
true: True
, 
guard: {T}
, 
rev_implies: P 
⇐ Q
, 
sub_cubical_set: Y ⊆ X
Lemmas referenced : 
implies-sub_cubical_set, 
context-subset_wf, 
face-and_wf, 
subset-cubical-term, 
context-subset-is-subset, 
face-type_wf, 
I_cube_pair_redex_lemma, 
face-and-eq-1, 
cubical-term-at_wf, 
subtype_rel_self, 
I_cube_wf, 
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, 
fset_wf, 
nat_wf, 
cube_set_restriction_pair_lemma, 
squash_wf, 
true_wf, 
istype-universe, 
face-term-at-restriction-eq-1, 
iff_weakening_equal, 
cube-set-restriction_wf, 
names-hom_wf, 
cubical-term_wf, 
cubical_set_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation_alt, 
introduction, 
cut, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
hypothesis, 
applyEquality, 
independent_isectElimination, 
instantiate, 
because_Cache, 
sqequalRule, 
lambdaFormation_alt, 
dependent_functionElimination, 
Error :memTop, 
lambdaEquality_alt, 
setElimination, 
rename, 
productElimination, 
independent_functionElimination, 
dependent_set_memberEquality_alt, 
equalityIstype, 
inhabitedIsType, 
equalityTransitivity, 
equalitySymmetry, 
setIsType, 
universeIsType, 
productEquality, 
cumulativity, 
isectEquality, 
imageElimination, 
universeEquality, 
natural_numberEquality, 
imageMemberEquality, 
baseClosed, 
independent_pairFormation, 
independent_pairEquality, 
axiomEquality, 
isect_memberEquality_alt, 
isectIsTypeImplies
Latex:
\mforall{}[Gamma:j\mvdash{}].  \mforall{}[phi,psi:\{Gamma  \mvdash{}  \_:\mBbbF{}\}].
    (sub\_cubical\_set\{j:l\}(Gamma,  (phi  \mwedge{}  psi);  Gamma,  psi,  phi)
    \mwedge{}  sub\_cubical\_set\{j:l\}(Gamma,  psi,  phi;  Gamma,  (phi  \mwedge{}  psi)))
Date html generated:
2020_05_20-PM-02_55_59
Last ObjectModification:
2020_04_04-PM-05_10_22
Theory : cubical!type!theory
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