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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