Nuprl Lemma : subset-presheaf-type
∀[C:SmallCategory]. ∀[X,Y:ps_context{j:l}(C)].  {X ⊢ _} ⊆r {Y ⊢ _} supposing sub_ps_context{j:l}(C; Y; X)
Proof
Definitions occuring in Statement : 
presheaf-type: {X ⊢ _}
, 
sub_ps_context: Y ⊆ X
, 
ps_context: __⊢
, 
uimplies: b supposing a
, 
subtype_rel: A ⊆r B
, 
uall: ∀[x:A]. B[x]
, 
small-category: SmallCategory
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
uimplies: b supposing a
, 
subtype_rel: A ⊆r B
, 
sub_ps_context: Y ⊆ X
, 
presheaf-type: {X ⊢ _}
, 
so_lambda: λ2x.t[x]
, 
so_apply: x[s]
, 
all: ∀x:A. B[x]
, 
squash: ↓T
, 
prop: ℙ
, 
true: True
, 
guard: {T}
, 
iff: P 
⇐⇒ Q
, 
and: P ∧ Q
, 
rev_implies: P 
⇐ Q
, 
implies: P 
⇒ Q
, 
pscm-id: 1(X)
, 
pscm-ap-type: (AF)s
, 
pscm-ap: (s)x
Lemmas referenced : 
subset-I_set, 
ps-subset-restriction, 
presheaf-type-equal, 
pscm-ap-type_wf, 
subtype_rel_product, 
cat-ob_wf, 
I_set_wf, 
cat-arrow_wf, 
psc-restriction_wf, 
istype-universe, 
subtype_rel_dep_function, 
subtype_rel-equal, 
equal_wf, 
squash_wf, 
true_wf, 
subtype_rel_self, 
iff_weakening_equal, 
presheaf-type_wf, 
sub_ps_context_wf, 
ps_context_wf, 
small-category-cumulativity-2, 
small-category_wf
Rules used in proof : 
cut, 
introduction, 
extract_by_obid, 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation_alt, 
hypothesis, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
independent_isectElimination, 
lambdaEquality_alt, 
setElimination, 
rename, 
applyEquality, 
instantiate, 
functionEquality, 
cumulativity, 
universeEquality, 
sqequalRule, 
functionIsType, 
universeIsType, 
because_Cache, 
lambdaFormation_alt, 
dependent_functionElimination, 
inhabitedIsType, 
imageElimination, 
equalityTransitivity, 
equalitySymmetry, 
natural_numberEquality, 
imageMemberEquality, 
baseClosed, 
productElimination, 
independent_functionElimination, 
dependent_pairEquality_alt, 
axiomEquality, 
functionExtensionality, 
hyp_replacement
Latex:
\mforall{}[C:SmallCategory].  \mforall{}[X,Y:ps\_context\{j:l\}(C)].
    \{X  \mvdash{}  \_\}  \msubseteq{}r  \{Y  \mvdash{}  \_\}  supposing  sub\_ps\_context\{j:l\}(C;  Y;  X)
Date html generated:
2020_05_20-PM-01_35_00
Last ObjectModification:
2020_04_02-PM-06_34_43
Theory : presheaf!models!of!type!theory
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