We study logical systems for reasoning about equations involving recursive definitions. In particular, we are interested in "propositional" fragments of the functional language of recursion FLR [18, 17], i.e., without the value passing or abstraction allowed in FLR. The "pure," propositional fragment FLR 0 turns out to coincide with the iteration theories of [1]. Our main focus here concerns the sharp contrast between the simple class of valid identities and the very complex consequence relation over several natural classes of models.

The influence of age and formal education on the development of moral reasoning in a Spanish sample of students was assessed by using a Spanish translation of Rest's Defining Issues Test. Our results support the hypothesis that moral development is highly related to both variables in our cultural context, although more so with formal education than with age.