Whether person, by signing letter purporting to “confirm his agreement” to terms of letter allegedly giving undertaking, is to be considered as having given undertaking - Whether unilateral contract may be effected in such manner - Whether consideration supplied or whether privity of contract established - Whether circumstances of particular relationship may give rise to duty of care - Whether representation of present fact intended to be acted upon and which is acted upon by another party may amount to a warranty and give rise to liability in damages - Expert evidence under the CPR.