*Let x, y be* partial words *and let m, n be positive integers such that **x*^{m} is compatible with *y*^{n}, (*x*^{m} ↑ *y*^{n})*, with *gcd(*m,n*) = 1*. Assume that for all i *∈ H(x) * the word*

*y*^{n}_{^} ( *i* )*y*^{n}_{^} ( *i + |x|* )*. . .y*^{n}_{^} ( *i + *( *m* - 1 )*|x|* )

*is *1-periodic *and that for all i *∈* H*(*y*)* the word *

*x*^{m}_{^} ( *i* )*x*^{m}_{^} ( *i + |y|* )*. . .x*^{m}_{^} ( *i + *( *n* - 1 )*|y|* )

*is *1*-periodic. A pair of partial words *(*x, y*)* which satisfies this property we will refer to as a *“*good pair*”*. Then there exists a partial word z such that* *x is *contained* in z *^{k}, (*x *⊂* z *^{k}),* and y *⊂* z *^{l} for some integers k, l.