Sun Mail Sir Lancelot

[redglenys]

stuck on 2, 16d not quite amateurs/ cry for help about prime development of these sportsmen [8] ?I?e,?u?,n?n
20d no longer in existence[7] /no longer around but included in arcane text
e?t?n?n

[Lie-in King]

16d Semipros
20d Extinct

[mac44]

semipros
extinct

[Lie-in King]

You're also showing the pattern for 13d - ?I?e,?u?,n?n - did you want that one as well, redglenys?

[redglenys]

thank you but I've missed another one 13 d necessary condition [4,3,3necessary condition 4,3,3/decorative sequinsoon becomes an indispensable condition [4,3,] ?I?e,,?u?,?n?n

[Lie-in King]

13d Sine qua non

[redglenys]

thank you both

[gangesboy]

sine qua non