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: List+ map: map(f;as) hd: hd(l) uall: [x:A]. B[x] apply: a function: x:A ⟶ B[x] universe: Type equal: 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: supposing a ge: i ≥  prop: implies:  Q so_lambda: λ2x.t[x] listp: 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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