Nuprl Lemma : bag-remove1-append1

∀[T:Type]. ∀[eq:EqDecider(T)]. ∀[x,y:T]. ∀[bs:bag(T)].
  (bag-remove1(eq;{y} + bs;x)
  = if eq x y then inl bs else case bag-remove1(eq;bs;x) of inl(as) => inl ({y} + as) | inr(x) => inr ⋅  fi 
  ∈ (bag(T)?))


Proof




Definitions occuring in Statement :  bag-remove1: bag-remove1(eq;bs;a),  bag-append: as + bs,  single-bag: {x},  bag: bag(T),  deq: EqDecider(T),  ifthenelse: if b then t else f fi ,  it: ⋅,  uall: ∀[x:A]. B[x],  unit: Unit,  apply: f a,  decide: case b of inl(x) => s[x] | inr(y) => t[y],  inr: inr x ,  inl: inl x,  union: left + right,  universe: Type,  equal: s = t ∈ T
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  deq: EqDecider(T),  all: ∀x:A. B[x],  implies: P ⇒ Q,  exposed-bfalse: exposed-bfalse,  bool: 𝔹,  unit: Unit,  it: ⋅,  btrue: tt,  uiff: uiff(P;Q),  and: P ∧ Q,  uimplies: b supposing a,  eqof: eqof(d),  ifthenelse: if b then t else f fi ,  squash: ↓T,  true: True,  subtype_rel: A ⊆r B,  guard: {T},  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q,  bfalse: ff,  exists: ∃x:A. B[x],  or: P ∨ Q,  sq_type: SQType(T),  bnot: ¬bb,  assert: ↑b,  false: False,  not: ¬A,  prop: ℙ,  isl: isl(x),  sq_or: a ↓∨ b
Lemmas referenced :  eqtt_to_assert,  safe-assert-deq,  equal_wf,  bag_wf,  unit_wf2,  bag-remove1_wf,  bag-append_wf,  single-bag_wf,  iff_weakening_equal,  bag-remove1-member,  eqff_to_assert,  bool_cases_sqequal,  subtype_base_sq,  bool_subtype_base,  assert-bnot,  iff_weakening_uiff,  assert_wf,  bag-remove1-property,  squash_wf,  true_wf,  istype-universe,  inl-one-one,  not-0-eq-1,  inr-one-one,  it_wf,  subtype_rel_self,  btrue_wf,  bfalse_wf,  btrue_neq_bfalse,  bag-append-assoc-comm,  bag-append-cancel,  bag-member-single,  bag-member_wf,  bag-member-append
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation_alt,  introduction,  cut,  applyEquality,  sqequalHypSubstitution,  setElimination,  thin,  rename,  hypothesisEquality,  hypothesis,  inhabitedIsType,  lambdaFormation_alt,  unionElimination,  equalityElimination,  extract_by_obid,  isectElimination,  equalityTransitivity,  equalitySymmetry,  productElimination,  independent_isectElimination,  sqequalRule,  lambdaEquality_alt,  imageElimination,  because_Cache,  universeIsType,  universeEquality,  unionEquality,  dependent_functionElimination,  natural_numberEquality,  imageMemberEquality,  baseClosed,  inlEquality_alt,  independent_functionElimination,  dependent_pairFormation_alt,  equalityIsType3,  promote_hyp,  instantiate,  voidElimination,  equalityIsType1,  isect_memberEquality_alt,  axiomEquality,  isectIsTypeImplies,  applyLambdaEquality,  inrEquality_alt,  dependent_set_memberEquality_alt,  independent_pairFormation,  productIsType,  inrFormation_alt,  inlFormation_alt

Latex:
\mforall{}[T:Type].  \mforall{}[eq:EqDecider(T)].  \mforall{}[x,y:T].  \mforall{}[bs:bag(T)].
    (bag-remove1(eq;\{y\}  +  bs;x)
    =  if  eq  x  y
        then  inl  bs
        else  case  bag-remove1(eq;bs;x)  of  inl(as)  =>  inl  (\{y\}  +  as)  |  inr(x)  =>  inr  \mcdot{} 
        fi  )



Date html generated: 2019_10_16-AM-11_31_08
Last ObjectModification: 2018_10_16-AM-09_34_29

Theory : bags_2


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