Absolute Retracts and Amalgamation in Certain Congruence Distributive Varieties
Peter Jipsen, H E Rose · Canadian Mathematical Bulletin · 1989
Abstract It is shown that if V is a congruence distributive variety whose members have one element subalgebras, then the class of absolute retracts of V is closed under direct products. If V is residually small, then a characterisation of the amalgamation class of V is given.