Nuprl Lemma : ps-sigma-unelim-elim-term
∀[C:SmallCategory]. ∀[X:ps_context{j:l}(C)]. ∀[A:{X ⊢ _}]. ∀[B:{X.A ⊢ _}]. ∀[T:{X.Σ A B ⊢ _}]. ∀[t:{X.Σ A B ⊢ _:T}].
  (((t)SigmaUnElim)SigmaElim = t ∈ {X.Σ A B ⊢ _:T})
Proof
Definitions occuring in Statement : 
sigma-unelim-pscm: SigmaUnElim
, 
sigma-elim-pscm: SigmaElim
, 
presheaf-sigma: Σ A B
, 
psc-adjoin: X.A
, 
pscm-ap-term: (t)s
, 
presheaf-term: {X ⊢ _:A}
, 
presheaf-type: {X ⊢ _}
, 
ps_context: __⊢
, 
uall: ∀[x:A]. B[x]
, 
equal: s = t ∈ T
, 
small-category: SmallCategory
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
and: P ∧ Q
, 
subtype_rel: A ⊆r B
, 
squash: ↓T
, 
prop: ℙ
, 
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
, 
all: ∀x:A. B[x]
, 
cat-comp: cat-comp(C)
, 
compose: f o g
, 
uimplies: b supposing a
, 
true: True
, 
guard: {T}
, 
iff: P 
⇐⇒ Q
, 
rev_implies: P 
⇐ Q
, 
implies: P 
⇒ Q
Lemmas referenced : 
ps-sigma-elim-unelim, 
presheaf-term_wf2, 
psc-adjoin_wf, 
ps_context_cumulativity2, 
presheaf-sigma_wf, 
presheaf-type-cumulativity2, 
presheaf-type_wf, 
small-category-cumulativity-2, 
ps_context_wf, 
small-category_wf, 
equal_wf, 
squash_wf, 
true_wf, 
istype-universe, 
pscm-ap-type-is-id, 
subtype_rel_self, 
psc_map_wf, 
pscm-id_wf, 
iff_weakening_equal, 
pscm-ap-term_wf, 
pscm-ap-comp-term, 
sigma-elim-pscm_wf, 
sigma-unelim-pscm_wf, 
pscm-ap-id-term
Rules used in proof : 
cut, 
introduction, 
extract_by_obid, 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation_alt, 
hypothesis, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
dependent_set_memberEquality_alt, 
independent_pairFormation, 
equalityTransitivity, 
equalitySymmetry, 
sqequalRule, 
productIsType, 
equalityIstype, 
inhabitedIsType, 
applyLambdaEquality, 
universeIsType, 
instantiate, 
applyEquality, 
because_Cache, 
isect_memberEquality_alt, 
axiomEquality, 
isectIsTypeImplies, 
setElimination, 
rename, 
productElimination, 
lambdaEquality_alt, 
imageElimination, 
universeEquality, 
independent_isectElimination, 
natural_numberEquality, 
imageMemberEquality, 
baseClosed, 
independent_functionElimination, 
hyp_replacement
Latex:
\mforall{}[C:SmallCategory].  \mforall{}[X:ps\_context\{j:l\}(C)].  \mforall{}[A:\{X  \mvdash{}  \_\}].  \mforall{}[B:\{X.A  \mvdash{}  \_\}].  \mforall{}[T:\{X.\mSigma{}  A  B  \mvdash{}  \_\}].
\mforall{}[t:\{X.\mSigma{}  A  B  \mvdash{}  \_:T\}].
    (((t)SigmaUnElim)SigmaElim  =  t)
Date html generated:
2020_05_20-PM-01_32_54
Last ObjectModification:
2020_04_03-AM-01_00_56
Theory : presheaf!models!of!type!theory
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