Nuprl Lemma : equiv_rel_squash
∀[T:Type]. ∀[E:T ⟶ T ⟶ ℙ].  (EquivRel(T;x,y.E[x;y]) 
⇒ EquivRel(T;x,y.↓E[x;y]))
Proof
Definitions occuring in Statement : 
equiv_rel: EquivRel(T;x,y.E[x; y])
, 
uall: ∀[x:A]. B[x]
, 
prop: ℙ
, 
so_apply: x[s1;s2]
, 
squash: ↓T
, 
implies: P 
⇒ Q
, 
function: x:A ⟶ B[x]
, 
universe: Type
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
implies: P 
⇒ Q
, 
so_lambda: λ2x y.t[x; y]
, 
so_apply: x[s1;s2]
, 
squash: ↓T
, 
prop: ℙ
, 
equiv_rel: EquivRel(T;x,y.E[x; y])
, 
and: P ∧ Q
, 
refl: Refl(T;x,y.E[x; y])
, 
all: ∀x:A. B[x]
, 
sym: Sym(T;x,y.E[x; y])
, 
trans: Trans(T;x,y.E[x; y])
Lemmas referenced : 
equiv_rel_squash2, 
equiv_rel_wf, 
istype-universe
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
Error :isect_memberFormation_alt, 
introduction, 
cut, 
Error :lambdaFormation_alt, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
sqequalRule, 
Error :lambdaEquality_alt, 
applyEquality, 
Error :inhabitedIsType, 
Error :universeIsType, 
independent_functionElimination, 
hypothesis, 
imageMemberEquality, 
baseClosed, 
dependent_functionElimination, 
productElimination, 
independent_pairEquality, 
imageElimination, 
Error :functionIsTypeImplies, 
Error :functionIsType, 
because_Cache, 
universeEquality, 
Error :isect_memberEquality_alt, 
Error :isectIsTypeImplies, 
instantiate
Latex:
\mforall{}[T:Type].  \mforall{}[E:T  {}\mrightarrow{}  T  {}\mrightarrow{}  \mBbbP{}].    (EquivRel(T;x,y.E[x;y])  {}\mRightarrow{}  EquivRel(T;x,y.\mdownarrow{}E[x;y]))
Date html generated:
2019_06_20-PM-00_28_51
Last ObjectModification:
2019_03_18-PM-07_10_11
Theory : rel_1
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