:: deftheorem Def15 defines n_w_n JORDAN5D:def 15 :
for g being non constant standard special_circular_sequence
for b₂ being Nat holds
( b₂ = n_w_n g iff ( 1 <= b₂ & b₂ + 1 <= len g & g . b₂ = N-min (L~ g) ) );