The composition pres o lady cannot be defined, since the value of the function lady has the name of a first lady as a function value, but the

The composition pres o lady cannot be defined, since the value of the function lady has the name of a first lady as a function value, but the function pres has the dates of presidential inauguration as domain values. The composition lady o pres CAN be defined. The function pres has range values from P, which can be substituted into the function lady. Symbolically, D-->P-->F, or the composition would bring D into P into F.