samer@4: function I=tween(a,b)
samer@4: % tween - all indices in a given range (like interval to set)
samer@4: %
samer@4: % tween :: interger, integer -> [[N]->integer].
samer@4: % tween :: [[2]->interger] -> [[N]->integer].
samer@4: %
samer@4: % tween([A,B])=tween(A,B).
samer@4: 
samer@4: if nargin<2, b=a(2); a=a(1); end
samer@4: if b>=a, I=a:b; else I=a:-1:b; end
samer@4: