[Help-glpk] K must be subscripted

[Daniele Micarelli]

Hi,
i have this situation:
....
set SLA;

set K{t in SLA};

param Deadline{t in SLA} ;

subject to DLINE{i in SLA}: sum{t in K} x[i,t]=1 ;
....

data;

set SLA := A17  A18  A25 ;

set K:= 0..Deadline ;

param Deadline :=

A17  32
A18  40
A25  44 ;
...

end;

but i get this error: K must be subscripted

how can i solve this error??

thank you very much