Nuprl Lemma : change-equality-type

∀[A,B:Type].  (respects-equality(A;B) ⇒ (∀x,y:A.  ((x = y ∈ A) ⇒ (x ∈ B) ⇒ (x = y ∈ B))))


Proof




Definitions occuring in Statement :  respects-equality: respects-equality(S;T),  uall: ∀[x:A]. B[x],  all: ∀x:A. B[x],  implies: P ⇒ Q,  member: t ∈ T,  universe: Type,  equal: s = t ∈ T
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  implies: P ⇒ Q,  all: ∀x:A. B[x],  member: t ∈ T,  respects-equality: respects-equality(S;T)
Lemmas referenced :  respects-equality_wf
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  Error :isect_memberFormation_alt,  Error :lambdaFormation_alt,  sqequalRule,  Error :equalityIstype,  Error :universeIsType,  hypothesisEquality,  cut,  hypothesis,  sqequalHypSubstitution,  dependent_functionElimination,  thin,  independent_functionElimination,  because_Cache,  introduction,  extract_by_obid,  isectElimination,  Error :inhabitedIsType,  universeEquality,  pointwiseFunctionalityForEquality,  equalityTransitivity,  equalitySymmetry

Latex:
\mforall{}[A,B:Type].    (respects-equality(A;B)  {}\mRightarrow{}  (\mforall{}x,y:A.    ((x  =  y)  {}\mRightarrow{}  (x  \mmember{}  B)  {}\mRightarrow{}  (x  =  y))))



Date html generated: 2019_06_20-AM-11_13_51
Last ObjectModification: 2018_11_28-PM-11_36_14

Theory : core_2


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