I have a problem of finding all regular intervals in the Coxeter group A9. When I use the code below for small groups A1 up to A4 I find the intervals. But for big groups like A7,A8 (these are symmetric groups S8 and S9), etc in sage 9.5 they say that the memory is full. Is there a way of cleaning the used memory so that I can get the last intervals? Because I want to see how the last few intervals look like. Down is the code.
W=WeylGroup('A9', prefix='s') [s1,s2,s3,s4,s5]=W.simple_reflections() S=W.simple_reflections() T=W.reflections() for u in W: for v in W: if u!=v and v!=W.long_element() and u.bruhat_le(v): K=Set([t for t in T if u.bruhat_le(tu) and (tu).bruhat_le(v)]) if K.cardinality()==v.length()-u.length(): print([u,v])