In some search petterns, only latin characters and numbers are accounted for as parts of names.
This needs to be extended.
Example: Greek characters with subscripts:
(%o21) ((-(%unitl_%_0*%unitq_%_0*(((x-%unitl_%_0/2)*abs(x-%unitl_%_0/2))/2+x^2/2))/2)-(%unitq_%_0*((((2*x^3)/3-2*%unitl_%_0*x^2+2*%unitl_%_0^2*x-(2*%unitl_%_0^3)/3)*signum(x-%unitl_%_0))/4+x^3/6))/2+(F_%_B*(((x-(3*%unitl_%_0)/2)*abs(x-(3*%unitl_%_0)/2))/2+x^2/2))/2+(Q_%_0*x^2)/2+(F_%_A*x^2)/2+M_%_0*x)/%unitEI
(%i22) integrate((-(%unitl_%_0*%unitq_%_0*(((x-%unitl_%_0/2)*abs(x-%unitl_%_0/2))/2+(x^2)/2))/2-(%unitq_%_0*((((2*x^3)/3-2*%unitl_%_0*x^2+2*%unitl_%_0^2*x-(2*%unitl_%_0^3)/3)*signum(x-%unitl_%_0))/4+(x^3)/6))/2+(F_%_B*(((x-(3*%unitl_%_0)/2)*abs(x-(3*%unitl_%_0)/2))/2+(x^2)/2))/2+(Q_%_0*x^2)/2+(F_%_A*x^2)/2+M_%_0*x)/%unitEI+φ.0,x);
incorrect syntax: 0.0 is not an infix operator
_%_0*x)/%unitEI+φ.0,