6 research outputs found
Monte Carlo Simulations of Sexual Reproduction
Modifying the Redfield model of sexual reproduction and the Penna model of
biological aging, we compare reproduction with and without recombination in
age-structured populations. In contrast to Redfield and in agreement with
Bernardes we find sexual reproduction to be preferred to asexual one. In
particular, the presence of old but still reproducing males helps the survival
of younger females beyond their reproductive age.Comment: 8 pages, plain tex, 7 EPS figures, to appear in PHYSICA
Syllogistic Logic with Cardinality Comparisons, On Infinite Sets
This article enlarges classical syllogistic logic with assertions having to do with comparisons between the sizes of sets. So it concerns a logical system whose sentences are of the following forms: All x are y and Some x are y, There are at least as many x as y, and There are more x than y. Here x and y range over subsets (not elements) of a given infinite set. Moreover, x and y may appear complemented (i.e., as x and y), with the natural meaning. We formulate a logic for our language that is based on the classical syllogistic. The main result is a soundness/completeness theorem. There are efficient algorithms for proof search and model construction