Nuprl Lemma : is-exception-evalall

[x:Base]. (is-exception(evalall(x))  (↓is-exception(x) ∨ (x)↓))


Proof




Definitions occuring in Statement :  has-value: (a)↓ is-exception: is-exception(t) evalall: evalall(t) uall: [x:A]. B[x] squash: T implies:  Q or: P ∨ Q base: Base
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T implies:  Q squash: T or: P ∨ Q prop: guard: {T} is-exception: is-exception(t) not: ¬A false: False
Lemmas referenced :  exception-not-bottom bottom_diverge base_wf is-exception_wf has-value_wf_base evalall-is-exception
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation introduction cut lambdaFormation exceptionSqequal hypothesis lemma_by_obid sqequalHypSubstitution isectElimination thin hypothesisEquality independent_functionElimination imageElimination unionElimination inlFormation sqequalRule inrFormation imageMemberEquality baseClosed baseApply closedConclusion lambdaEquality dependent_functionElimination divergentSqle sqleRule voidElimination because_Cache

Latex:
\mforall{}[x:Base].  (is-exception(evalall(x))  {}\mRightarrow{}  (\mdownarrow{}is-exception(x)  \mvee{}  (x)\mdownarrow{}))



Date html generated: 2016_05_13-PM-03_28_39
Last ObjectModification: 2016_01_14-PM-06_41_59

Theory : arithmetic


Home Index