
Technical Report: DCC9812
Counting a type's principal inhabitants
Sabine Broda and Luís Damas
DCCFC & LIACC, Universidade do Porto
R. do Campo Alegre 823, 4150 Porto, Portugal
Phone: 351 22 6078830, Fax: 351 22 6003654
Email: {sbb,luis}@ncc.up.pt}
December 1998
Abstract
We present a Counting Algorithm that computes the number of
$\lambda$terms in $\beta$normal form that have a given type
$\tau$ as a principal type and produces a list of these terms. The
design of the algorithm follows the lines of BenYelles' algorithm for
counting normal (not necessarily principal)
inhabitants of a type $\tau$.
