samer@4: % tail_return - Package return values for tail_feval
samer@4: %
samer@4: % tail_return :: A{1:N} -> thunk(A{1:N}).
samer@4: %
samer@4: % thunk(B{1:M}) ::= 
samer@4: %    exists C{1:L} . cell { C{1:L}->B{1:M}, cell { C{1:L} } }
samer@4: %  | cell { {0}, cell { B{1:L} } }
samer@12: %  | void -> B{1:M}.
samer@4: function ret=tail_return(varargin), ret={0,varargin}; end