NF = 3 $1 = <> $2 = <> $3 = <3> NF = 3 $1 = <> $2 = <> $3 = <3> NF = 7 $1 = <> $2 = <> $3 = <a> $4 = <> $5 = <b> $6 = <> $7 = <> NF = 7 $1 = <> $2 = <> $3 = <a> $4 = <> $5 = <b> $6 = <> $7 = <> NF = 3 $1 = <"a"> $2 = <> $3 = <"b"> NF = 0 NF = 0 NF = 1 $1 = <""> NF = 1 $1 = <""> NF = 1 $1 = <xx> NF = 1 $1 = <xx> NF = 2 $1 = <> $2 = <> NF = 2 $1 = <> $2 = <>