The lrepeat command creates a list of size number * number of elements by repeating number times the sequence of elements element1 element2 .... number must be a positive integer, elementn can be any Tcl value. Note that lrepeat 1 arg ... is identical to list arg ..., though the arg is required with lrepeat.
lrepeat 3 a
-> a a a
lrepeat 3 [lrepeat 3 0]
-> {0 0 0} {0 0 0} {0 0 0}
lrepeat 3 a b c
-> a b c a b c a b c
lrepeat 3 [lrepeat 2 a] b c
-> {a a} b c {a a} b c {a a} b c