Nuprl Lemma : composition-function-cumulativity
∀Gamma:j⊢. ∀Z:{Gamma ⊢ _}.  (composition-function{[i | j]:l, i:l}(Gamma; Z) ⊆r composition-function{j:l,i:l}(Gamma;Z))
Proof
Definitions occuring in Statement : 
composition-function: composition-function{j:l,i:l}(Gamma;A)
, 
cubical-type: {X ⊢ _}
, 
cubical_set: CubicalSet
, 
subtype_rel: A ⊆r B
, 
all: ∀x:A. B[x]
Definitions unfolded in proof : 
all: ∀x:A. B[x]
, 
subtype_rel: A ⊆r B
, 
member: t ∈ T
, 
composition-function: composition-function{j:l,i:l}(Gamma;A)
, 
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
, 
names-hom: I ⟶ J
, 
cat-comp: cat-comp(C)
, 
compose: f o g
, 
uall: ∀[x:A]. B[x]
Lemmas referenced : 
cubical_set_cumulativity-i-j, 
subtype_rel_self, 
cube_set_map_wf, 
cube-context-adjoin_wf, 
interval-type_wf, 
cubical_set_wf, 
composition-function_wf, 
cubical-type_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation_alt, 
lambdaEquality_alt, 
sqequalHypSubstitution, 
functionExtensionality, 
applyEquality, 
hypothesisEquality, 
cut, 
thin, 
instantiate, 
introduction, 
extract_by_obid, 
hypothesis, 
sqequalRule, 
isectElimination, 
because_Cache, 
universeIsType
Latex:
\mforall{}Gamma:j\mvdash{}.  \mforall{}Z:\{Gamma  \mvdash{}  \_\}.
    (composition-function\{[i  |  j]:l,  i:l\}(Gamma;  Z)  \msubseteq{}r  composition-function\{j:l,i:l\}(Gamma;Z))
Date html generated:
2020_05_20-PM-04_21_05
Last ObjectModification:
2020_04_14-AM-01_23_55
Theory : cubical!type!theory
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