1? DIMENSION
2 (
3+ ,
3 %bound
4 )
5 %bound:
6? 
6 %lower-bound
6.1 -:
6 *:
7 %upper-bound
7 *

lower-bound:

1! 1
1?
1 expression
1.1? REFER(variable)

upper-bound:

1 expression
2? REFER(variable)