Nuprl Lemma : pscm-presheaf-sigma-typed
∀C:SmallCategory. ∀X,Delta:ps_context{j:l}(C). ∀A:{X ⊢ _}. ∀B:{X.A ⊢ _}. ∀s:psc_map{j:l}(C; Delta; X).
  ((Σ A B)s = Σ (A)s (B)(s)dep ∈ {Delta ⊢ _})
Proof
Definitions occuring in Statement : 
presheaf-sigma: Σ A B
, 
pscm-dependent: (s)dep
, 
psc-adjoin: X.A
, 
pscm-ap-type: (AF)s
, 
presheaf-type: {X ⊢ _}
, 
psc_map: A ⟶ B
, 
ps_context: __⊢
, 
all: ∀x:A. B[x]
, 
equal: s = t ∈ T
, 
small-category: SmallCategory
Definitions unfolded in proof : 
all: ∀x:A. B[x]
, 
member: t ∈ T
, 
uall: ∀[x:A]. B[x]
, 
subtype_rel: A ⊆r 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, 
cat-arrow: cat-arrow(C)
, 
pi2: snd(t)
, 
type-cat: TypeCat
, 
cat-comp: cat-comp(C)
, 
compose: f o g
, 
pscm-dependent: (s)dep
, 
typed-psc-snd: tq
, 
typed-psc-fst: tp{i:l}
Lemmas referenced : 
pscm-ap-type_wf, 
psc-adjoin_wf, 
ps_context_cumulativity2, 
presheaf-type-cumulativity2, 
pscm-dependent_wf, 
subtype_rel_self, 
psc_map_wf, 
small-category-cumulativity-2, 
presheaf-type_wf, 
ps_context_wf, 
small-category_wf, 
pscm-presheaf-sigma
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation_alt, 
cut, 
thin, 
instantiate, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
hypothesisEquality, 
applyEquality, 
because_Cache, 
hypothesis, 
sqequalRule, 
dependent_functionElimination, 
universeIsType
Latex:
\mforall{}C:SmallCategory.  \mforall{}X,Delta:ps\_context\{j:l\}(C).  \mforall{}A:\{X  \mvdash{}  \_\}.  \mforall{}B:\{X.A  \mvdash{}  \_\}.
\mforall{}s:psc\_map\{j:l\}(C;  Delta;  X).
    ((\mSigma{}  A  B)s  =  \mSigma{}  (A)s  (B)(s)dep)
Date html generated:
2020_05_20-PM-01_31_38
Last ObjectModification:
2020_04_02-PM-03_03_55
Theory : presheaf!models!of!type!theory
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