The formal solution of the homogeneous linear differential equation $$ x^{(n)}(łambda)+a_{n-1}(łambda)x^{(n-1)}(łambda)+\cdots +a_0(łambda)x(łambda)=0, 0łełambdałeŁambda $$ is considered. $x(\lambda)$ and $a_i(\lambda)$ are functions which map the interval $[0,\Lambda]$ into the field $M$ of Mikusinski operators [2].