Nuprl Lemma : extend-type-equiv
∀[T:Type]. EquivRel(Base;x,y.(x ∈ T ⇐⇒ y ∈ T) ∧ ((x ∈ T) ⇒ (x = y ∈ T)))
Proof
Definitions occuring in Statement : 
equiv_rel: EquivRel(T;x,y.E[x; y]), 
uall: ∀[x:A]. B[x], 
iff: P ⇐⇒ Q, 
implies: P ⇒ Q, 
and: P ∧ Q, 
member: t ∈ T, 
base: Base, 
universe: Type, 
equal: s = t ∈ T
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x], 
member: t ∈ T, 
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], 
cand: A c∧ B, 
iff: P ⇐⇒ Q, 
implies: P ⇒ Q, 
rev_implies: P ⇐ Q, 
sym: Sym(T;x,y.E[x; y]), 
trans: Trans(T;x,y.E[x; y])
Lemmas referenced : 
istype-base, 
istype-universe
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
Error :isect_memberFormation_alt, 
introduction, 
cut, 
independent_pairFormation, 
Error :lambdaFormation_alt, 
sqequalHypSubstitution, 
equalityTransitivity, 
hypothesis, 
equalitySymmetry, 
sqequalRule, 
Error :equalityIstype, 
Error :universeIsType, 
hypothesisEquality, 
sqequalBase, 
because_Cache, 
productElimination, 
thin, 
extract_by_obid, 
independent_functionElimination, 
Error :productIsType, 
Error :functionIsType, 
independent_pairEquality, 
Error :lambdaEquality_alt, 
dependent_functionElimination, 
axiomEquality, 
Error :functionIsTypeImplies, 
Error :inhabitedIsType, 
instantiate, 
isectElimination, 
universeEquality
Latex:
\mforall{}[T:Type].  EquivRel(Base;x,y.(x  \mmember{}  T  \mLeftarrow{}{}\mRightarrow{}  y  \mmember{}  T)  \mwedge{}  ((x  \mmember{}  T)  {}\mRightarrow{}  (x  =  y)))
Date html generated:
2019_06_20-PM-00_33_20
Last ObjectModification:
2018_11_25-PM-06_36_28
Theory : quot_1
Home
Index