Compresses the symbol pattern having a given length pattern using quantisation of min-len. This function is used to restore expand-with-len pattern back to normal.
(expand-with-len '(a b c d) '(1/16. 1/8) '1/1 '1/32)
--> (a a a b b b b c c c d d d d a a a b b b b c c c d d d d a a a b b b b)
(compress-with-len '(a a a b b b b c c c d d d d a a a b b b b c c c d d d d a a a b b b b)