Nuprl Lemma : lifting-spread-less

∀[a,b,c,d,H:Top].
  (let x,y = if (a) < (b)  then c  else d 
   in H[x;y] ~ if (a) < (b)  then let x,y = c in H[x;y]  else let x,y = d in H[x;y])


Proof




Definitions occuring in Statement :  uall: ∀[x:A]. B[x],  top: Top,  so_apply: x[s1;s2],  less: if (a) < (b)  then c  else d,  spread: spread def,  sqequal: s ~ t
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  so_lambda: so_lambda(x,y,z,w.t[x; y; z; w]),  so_apply: x[s1;s2;s3;s4],  so_lambda: λ2x y.t[x; y],  top: Top,  so_apply: x[s1;s2],  uimplies: b supposing a,  strict4: strict4(F),  and: P ∧ Q,  all: ∀x:A. B[x],  implies: P ⇒ Q,  has-value: (a)↓,  prop: ℙ,  guard: {T},  or: P ∨ Q,  squash: ↓T
Lemmas referenced :  lifting-strict-less,  top_wf,  equal_wf,  has-value_wf_base,  base_wf,  is-exception_wf
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  introduction,  cut,  sqequalRule,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  thin,  baseClosed,  isect_memberEquality,  voidElimination,  voidEquality,  independent_isectElimination,  independent_pairFormation,  lambdaFormation,  callbyvalueSpread,  hypothesis,  equalityTransitivity,  equalitySymmetry,  productEquality,  productElimination,  sqleReflexivity,  hypothesisEquality,  dependent_functionElimination,  independent_functionElimination,  baseApply,  closedConclusion,  spreadExceptionCases,  inrFormation,  because_Cache,  imageMemberEquality,  imageElimination,  exceptionSqequal,  inlFormation,  sqequalAxiom

Latex:
\mforall{}[a,b,c,d,H:Top].
    (let  x,y  =  if  (a)  <  (b)    then  c    else  d 
      in  H[x;y]  \msim{}  if  (a)  <  (b)    then  let  x,y  =  c  in  H[x;y]    else  let  x,y  =  d  in  H[x;y])



Date html generated: 2017_04_14-AM-07_20_57
Last ObjectModification: 2017_02_27-PM-02_54_32

Theory : computation


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