The symmetry approach to the description of the (P,T) phase diagram of
ferromagnet superconductors with triplet pairing is developed. Taking into
account the recent experimental observations made on UCoGe it is considered the
case of a crystal with orthorhombic structure and strong spin-orbital coupling.
It is shown that formation of ferromagnet superconducting state from a
superconducting state is inevitably accompanied by the first order type
transition.Comment: 4 pages, 1 figur