Nuprl Lemma : hd_map

∀[T,T':Type]. ∀[a:T List+]. ∀[f:T ⟶ T'].  (hd(map(f;a)) = (f hd(a)) ∈ T')


Proof




Definitions occuring in Statement :  listp: A List+,  map: map(f;as),  hd: hd(l),  uall: ∀[x:A]. B[x],  apply: f a,  function: x:A ⟶ B[x],  universe: Type,  equal: s = t ∈ T
Definitions unfolded in proof :  member: t ∈ T,  uall: ∀[x:A]. B[x],  true: True,  less_than': less_than'(a;b),  so_apply: x[s],  not: ¬A,  false: False,  exists: ∃x:A. B[x],  satisfiable_int_formula: satisfiable_int_formula(fmla),  and: P ∧ Q,  le: A ≤ B,  or: P ∨ Q,  decidable: Dec(P),  all: ∀x:A. B[x],  top: Top,  uimplies: b supposing a,  ge: i ≥ j ,  prop: ℙ,  implies: P ⇒ Q,  so_lambda: λ2x.t[x],  listp: A List+
Lemmas referenced :  listp_wf,  reduce_hd_cons_lemma,  map_cons_lemma,  length_of_cons_lemma,  map_nil_lemma,  length_of_nil_lemma,  list_wf,  less_than_wf,  int_formula_prop_wf,  int_formula_prop_le_lemma,  int_term_value_var_lemma,  int_term_value_constant_lemma,  int_formula_prop_less_lemma,  int_formula_prop_not_lemma,  int_formula_prop_and_lemma,  intformle_wf,  itermVar_wf,  itermConstant_wf,  intformless_wf,  intformnot_wf,  intformand_wf,  satisfiable-full-omega-tt,  decidable__lt,  map-length,  map_wf,  hd_wf,  equal_wf,  length_wf,  ge_wf,  list_induction,  listp_properties
Rules used in proof :  functionIsType,  universeIsType,  hypothesisEquality,  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  functionEquality,  cut,  introduction,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  thin,  hypothesis,  because_Cache,  inhabitedIsType,  universeEquality,  isect_memberFormation_alt,  sqequalRule,  isect_memberEquality,  axiomEquality,  addEquality,  lambdaFormation,  independent_functionElimination,  dependent_set_memberEquality,  computeAll,  independent_pairFormation,  intEquality,  int_eqEquality,  dependent_pairFormation,  productElimination,  unionElimination,  dependent_functionElimination,  voidEquality,  voidElimination,  independent_isectElimination,  applyEquality,  functionExtensionality,  natural_numberEquality,  cumulativity,  lambdaEquality,  rename,  setElimination

Latex:
\mforall{}[T,T':Type].  \mforall{}[a:T  List\msupplus{}].  \mforall{}[f:T  {}\mrightarrow{}  T'].    (hd(map(f;a))  =  (f  hd(a)))



Date html generated: 2019_10_15-AM-10_53_25
Last ObjectModification: 2018_09_27-AM-10_02_47

Theory : list!


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