Nuprl Lemma : has-value-extensionality

[a,b:Base].  (a)↓ (b)↓ ∈ ℙ supposing (a)↓ ⇐⇒ (b)↓


Proof




Definitions occuring in Statement :  has-value: (a)↓ uimplies: supposing a uall: [x:A]. B[x] prop: iff: ⇐⇒ Q base: Base equal: t ∈ T
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T uimplies: supposing a iff: ⇐⇒ Q and: P ∧ Q has-value: (a)↓ prop: implies:  Q rev_implies:  Q squash: T
Lemmas referenced :  has-value_wf_base istype-base
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity Error :isect_memberFormation_alt,  introduction cut sqequalHypSubstitution productElimination thin sqleExtensionalEquality independent_pairFormation Error :lambdaFormation_alt,  independent_functionElimination hypothesis Error :universeIsType,  extract_by_obid isectElimination hypothesisEquality sqequalRule imageMemberEquality baseClosed Error :productIsType,  Error :functionIsType,  because_Cache Error :isect_memberEquality_alt,  axiomEquality Error :isectIsTypeImplies,  Error :inhabitedIsType

Latex:
\mforall{}[a,b:Base].    (a)\mdownarrow{}  =  (b)\mdownarrow{}  supposing  (a)\mdownarrow{}  \mLeftarrow{}{}\mRightarrow{}  (b)\mdownarrow{}



Date html generated: 2019_06_20-AM-11_20_34
Last ObjectModification: 2018_10_16-PM-01_47_32

Theory : call!by!value_1


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