Nuprl Lemma : rank-pi-choices

[P:pi_term()]. ∀[choice:{c:pi_prefix() × pi_term()| (c ∈ pi-choices(P))} ].  pi-rank(snd(choice)) < pi-rank(P)


Proof




Definitions occuring in Statement :  pi-choices: pi-choices(t) pi-rank: pi-rank(p) pi_term: pi_term() pi_prefix: pi_prefix() l_member: (x ∈ l) less_than: a < b uall: [x:A]. B[x] pi2: snd(t) set: {x:A| B[x]}  product: x:A × B[x]
Lemmas :  pi_term-induction all_wf l_member_wf pi-choices_wf less_than_wf pi-rank_wf nat_wf null_nil_lemma btrue_wf member-implies-null-eq-bfalse pi_prefix_wf pi_term_wf nil_wf btrue_neq_bfalse set_wf member_singleton cons_wf member_append append_wf name_wf member-less_than decidable__lt false_wf condition-implies-le minus-add minus-one-mul add-swap add-commutes add-mul-special zero-mul add-zero add-associates le-add-cancel

Latex:
\mforall{}[P:pi\_term()].  \mforall{}[choice:\{c:pi\_prefix()  \mtimes{}  pi\_term()|  (c  \mmember{}  pi-choices(P))\}  ].
    pi-rank(snd(choice))  <  pi-rank(P)



Date html generated: 2015_07_23-AM-11_33_58
Last ObjectModification: 2015_01_29-AM-00_55_31

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