Nuprl Lemma : tree-height_wf

[x:Type]. ∀[t:tree(x)].  (tree-height(t) ∈ ℕ)


Proof




Definitions occuring in Statement :  tree-height: tree-height(t) tree: tree(E) nat: uall: [x:A]. B[x] member: t ∈ T universe: Type
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T tree-height: tree-height(t) subtype_rel: A ⊆B uimplies: supposing a top: Top so_lambda: λ2x.t[x] nat: le: A ≤ B and: P ∧ Q less_than': less_than'(a;b) false: False not: ¬A implies:  Q prop: so_apply: x[s] so_lambda: so_lambda(x,y,z,w.t[x; y; z; w]) all: x:A. B[x] guard: {T} ge: i ≥  decidable: Dec(P) or: P ∨ Q satisfiable_int_formula: satisfiable_int_formula(fmla) exists: x:A. B[x] so_apply: x[s1;s2;s3;s4]
Lemmas referenced :  tree_ind_wf_simple top_wf nat_wf tree_subtype false_wf le_wf imax_wf imax_nat nat_properties decidable__le satisfiable-full-omega-tt intformand_wf intformnot_wf intformle_wf itermConstant_wf itermVar_wf intformeq_wf int_formula_prop_and_lemma int_formula_prop_not_lemma int_formula_prop_le_lemma int_term_value_constant_lemma int_term_value_var_lemma int_formula_prop_eq_lemma int_formula_prop_wf equal_wf tree_wf
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation introduction cut sqequalRule extract_by_obid sqequalHypSubstitution isectElimination thin hypothesis hypothesisEquality applyEquality independent_isectElimination lambdaEquality isect_memberEquality voidElimination voidEquality because_Cache dependent_set_memberEquality natural_numberEquality independent_pairFormation lambdaFormation setElimination rename equalityTransitivity equalitySymmetry applyLambdaEquality dependent_functionElimination unionElimination dependent_pairFormation int_eqEquality intEquality computeAll independent_functionElimination axiomEquality cumulativity universeEquality

Latex:
\mforall{}[x:Type].  \mforall{}[t:tree(x)].    (tree-height(t)  \mmember{}  \mBbbN{})



Date html generated: 2017_10_01-AM-08_30_42
Last ObjectModification: 2017_05_02-AM-10_59_05

Theory : tree_1


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