Definition: Let x be a string over S.
For i ³ 0, the i-th power of x, xi, is defined as
1) x0 = e 2) if i ³ 1 then xi = xxi-1
Note: xixj = xjxi = xi+j, where i, j ³ 0
Example: Consider x =10
Task: x3
x3 = xx2 = 10x2
x0 = e
x2 = xx1 = 10x1
x1 = xx0 = 10x0
x1 = 10e = 10
x2 = 1010
x3 = 101010
Power of String
 Gist: xi = xx…x
i-times
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