Nuprl Lemma : subterm-size

∀[opr:Type]. ∀[s,t:term(opr)].  (s << t ⇒ term-size(s) < term-size(t))


Proof




Definitions occuring in Statement :  subterm: s << t,  term-size: term-size(t),  term: term(opr),  less_than: a < b,  uall: ∀[x:A]. B[x],  implies: P ⇒ Q,  universe: Type
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  implies: P ⇒ Q,  subterm: s << t,  subtype_rel: A ⊆r B,  rel_implies: R1 => R2,  all: ∀x:A. B[x],  infix_ap: x f y,  prop: ℙ,  trans: Trans(T;x,y.E[x; y]),  decidable: Dec(P),  or: P ∨ Q,  less_than: a < b,  squash: ↓T,  and: P ∧ Q,  uimplies: b supposing a,  not: ¬A,  satisfiable_int_formula: satisfiable_int_formula(fmla),  exists: ∃x:A. B[x],  false: False,  subterm-rel: subterm-rel(opr),  nat: ℕ
Lemmas referenced :  transitive-closure-minimal-ext,  immediate-subterm_wf,  less_than_wf,  term-size_wf,  immediate-subterm-size,  decidable__lt,  full-omega-unsat,  intformand_wf,  intformnot_wf,  intformless_wf,  itermVar_wf,  istype-int,  int_formula_prop_and_lemma,  int_formula_prop_not_lemma,  int_formula_prop_less_lemma,  int_term_value_var_lemma,  int_formula_prop_wf,  istype-less_than,  subterm_wf,  member-less_than,  term_wf,  istype-universe
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation_alt,  introduction,  cut,  lambdaFormation_alt,  sqequalHypSubstitution,  extract_by_obid,  isectElimination,  thin,  because_Cache,  lambdaEquality_alt,  hypothesisEquality,  hypothesis,  inhabitedIsType,  applyEquality,  sqequalRule,  independent_functionElimination,  universeIsType,  dependent_functionElimination,  unionElimination,  imageElimination,  productElimination,  natural_numberEquality,  independent_isectElimination,  approximateComputation,  dependent_pairFormation_alt,  int_eqEquality,  Error :memTop,  independent_pairFormation,  voidElimination,  setElimination,  rename,  equalityTransitivity,  equalitySymmetry,  functionIsTypeImplies,  isect_memberEquality_alt,  isectIsTypeImplies,  instantiate,  universeEquality

Latex:
\mforall{}[opr:Type].  \mforall{}[s,t:term(opr)].    (s  <<  t  {}\mRightarrow{}  term-size(s)  <  term-size(t))



Date html generated: 2020_05_19-PM-09_54_14
Last ObjectModification: 2020_03_09-PM-04_36_46

Theory : terms


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