Nuprl Lemma : sub_cubical_set-cumulativity1
∀[Y,X:j⊢].  sub_cubical_set{[j | i]:l}(Y; X) supposing sub_cubical_set{j:l}(Y; X)
Proof
Definitions occuring in Statement : 
sub_cubical_set: Y ⊆ X
, 
cubical_set: CubicalSet
, 
uimplies: b supposing a
, 
uall: ∀[x:A]. B[x]
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
uimplies: b supposing a
, 
sub_cubical_set: Y ⊆ X
, 
subtype_rel: A ⊆r B
, 
guard: {T}
, 
cube_set_map: A ⟶ B
, 
psc_map: A ⟶ B
, 
nat-trans: nat-trans(C;D;F;G)
, 
cat-ob: cat-ob(C)
, 
pi1: fst(t)
, 
op-cat: op-cat(C)
, 
spreadn: spread4, 
cube-cat: CubeCat
, 
fset: fset(T)
, 
quotient: x,y:A//B[x; y]
, 
cat-arrow: cat-arrow(C)
, 
pi2: snd(t)
, 
type-cat: TypeCat
, 
all: ∀x:A. B[x]
, 
names-hom: I ⟶ J
, 
cat-comp: cat-comp(C)
, 
compose: f o g
Lemmas referenced : 
subtype_rel_self, 
cube_set_map_wf, 
cubical_set_cumulativity-i-j, 
sub_cubical_set_wf, 
cubical_set_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation_alt, 
introduction, 
cut, 
sqequalHypSubstitution, 
equalityTransitivity, 
hypothesis, 
equalitySymmetry, 
applyEquality, 
sqequalRule, 
thin, 
instantiate, 
extract_by_obid, 
isectElimination, 
hypothesisEquality, 
because_Cache, 
axiomEquality, 
universeIsType, 
isect_memberEquality_alt, 
isectIsTypeImplies, 
inhabitedIsType
Latex:
\mforall{}[Y,X:j\mvdash{}].    sub\_cubical\_set\{[j  |  i]:l\}(Y;  X)  supposing  sub\_cubical\_set\{j:l\}(Y;  X)
Date html generated:
2020_05_20-PM-01_43_05
Last ObjectModification:
2020_04_06-PM-00_14_43
Theory : cubical!type!theory
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