:: deftheorem Def16 defines n_e_n JORDAN5D:def 16 :
for g being non constant standard special_circular_sequence
for b₂ being Nat holds
( b₂ = n_e_n g iff ( 1 <= b₂ & b₂ + 1 <= len g & g . b₂ = N-max (L~ g) ) );