### Nuprl Lemma : decide-isatom-if-has-value

`∀t,a,b:Base.  ((t)↓ `` ((if t is an atom then a otherwise b ~ a) ∨ (if t is an atom then a otherwise b ~ b)))`

Proof

Definitions occuring in Statement :  has-value: `(a)↓` isatom: `if z is an atom then a otherwise b` all: `∀x:A. B[x]` implies: `P `` Q` or: `P ∨ Q` base: `Base` sqequal: `s ~ t`
Definitions unfolded in proof :  all: `∀x:A. B[x]` implies: `P `` Q` has-value: `(a)↓` member: `t ∈ T` uall: `∀[x:A]. B[x]` or: `P ∨ Q` top: `Top` guard: `{T}` prop: `ℙ`
Lemmas referenced :  base_wf top_wf is-exception_wf has-value_wf_base
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity lambdaFormation isatomCases divergentSqle hypothesis cut lemma_by_obid sqequalHypSubstitution isectElimination thin baseClosed hypothesisEquality sqequalRule isatomReduceTrue equalityTransitivity equalitySymmetry because_Cache inlFormation sqequalIntensionalEquality isect_memberFormation introduction sqequalAxiom isect_memberEquality voidElimination voidEquality inrFormation

Latex:
\mforall{}t,a,b:Base.
((t)\mdownarrow{}  {}\mRightarrow{}  ((if  t  is  an  atom  then  a  otherwise  b  \msim{}  a)  \mvee{}  (if  t  is  an  atom  then  a  otherwise  b  \msim{}  b)))

Date html generated: 2016_05_13-PM-03_22_31
Last ObjectModification: 2016_01_14-PM-06_46_41

Theory : call!by!value_1

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