Nuprl Lemma : trivial-record-update

∀[r,z:Top].  (r[z := r.z] ~ λx.if x =a z then r x else r x fi )


Proof




Definitions occuring in Statement :  record-update: r[x := v],  record-select: r.x,  ifthenelse: if b then t else f fi ,  eq_atom: x =a y,  uall: ∀[x:A]. B[x],  top: Top,  apply: f a,  lambda: λx.A[x],  sqequal: s ~ t
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  record-select: r.x,  record-update: r[x := v],  eq_atom: x =a y,  ifthenelse: if b then t else f fi ,  btrue: tt,  bfalse: ff,  it: ⋅,  so_lambda: so_lambda(x,y,z,w.t[x; y; z; w]),  so_apply: x[s1;s2;s3;s4],  so_lambda: λ2x.t[x],  top: Top,  so_apply: x[s],  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-atom_eq,  top_wf,  equal_wf,  has-value_wf_base,  base_wf,  is-exception_wf,  atom_eq_sq_normalize
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,  callbyvalueDecide,  hypothesis,  hypothesisEquality,  equalityTransitivity,  equalitySymmetry,  unionEquality,  unionElimination,  sqleReflexivity,  dependent_functionElimination,  independent_functionElimination,  baseApply,  closedConclusion,  decideExceptionCases,  inrFormation,  because_Cache,  imageMemberEquality,  imageElimination,  exceptionSqequal,  inlFormation,  instantiate,  rename,  sqequalAxiom

Latex:
\mforall{}[r,z:Top].    (r[z  :=  r.z]  \msim{}  \mlambda{}x.if  x  =a  z  then  r  x  else  r  x  fi  )



Date html generated: 2018_05_21-PM-08_40_04
Last ObjectModification: 2017_07_26-PM-06_04_09

Theory : general


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