Nuprl Lemma : rank-option-decompose
∀[P:pi_term()]. pi-rank(P) = ((pi-rank(pioption-left(P)) + pi-rank(pioption-right(P))) + 1) ∈ ℕ supposing ↑pioption?(P)
Proof
Definitions occuring in Statement : 
pi-rank: pi-rank(p)
, 
pioption-right: pioption-right(v)
, 
pioption-left: pioption-left(v)
, 
pioption?: pioption?(v)
, 
pi_term: pi_term()
, 
nat: ℕ
, 
assert: ↑b
, 
uimplies: b supposing a
, 
uall: ∀[x:A]. B[x]
, 
add: n + m
, 
natural_number: $n
, 
equal: s = t ∈ T
Lemmas : 
assert_wf, 
pioption?_wf, 
pi_term_wf, 
pi-option-decompose, 
rank-option, 
pioption-left_wf, 
pioption-right_wf, 
zero-le-nat, 
pi-rank_wf, 
squash_wf, 
true_wf, 
nat_wf, 
iff_weakening_equal, 
le_wf
Latex:
\mforall{}[P:pi\_term()]
    pi-rank(P)  =  ((pi-rank(pioption-left(P))  +  pi-rank(pioption-right(P)))  +  1) 
    supposing  \muparrow{}pioption?(P)
Date html generated:
2015_07_23-AM-11_33_12
Last ObjectModification:
2015_02_04-PM-03_43_34
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