  We derive gap equations for superconductivity in coexistence with
ferromagnetism. We treat singlet states and triplet states with either equal
spin pairing (ESP) or opposite spin pairing (OSP) states, and study the
behaviour of these states as a function of exchange splitting. For the s-wave
singlet state we find that our gap equations correctly reproduce the
Clogston--Chandrasekhar limiting behaviour and the phase diagram of the
Baltensperger--Sarma equation (excluding the FFLO region). The singlet
superconducting order parameter is shown to be independent of exchange
splitting at zero temperature, as is assumed in the derivation of the
Clogston--Chandrasekhar limit. P-wave triplet states of the OSP type, behave
similarly to the singlet state as a function of exchange splitting. On the
other hand, ESP triplet states show a very different behaviour. In particular
there is no Clogston--Chandrasekhar limiting and the superconducting critical
temperature is actually increased by exchange splitting.
