The theory of temperature programming has been reexamined. It is shown that a linear program leads to an explicit relation for the retention temperature in terms of the inverse exponential integral. Numerical examples are solved using a straight line plot of the exponential integral together with a plot based on the equivalent temperature concept. A simple explicit expression in terms of common functions for the retention temperature during linear temperature programming was deduced. This was made possible using the inverse log nonlinear program which can be made to approximate quite closely a linear program. This expression was used to explain the constancy of intervals and other phenomena encountered during the linear temperature programming of homologous series.