An algebraic theory of normal forms

Silvio Ghilardi
1995 Annals of Pure and Applied Logic  
0168-0072/95/$09.50 JJ 1995 --Elsevier Science B.V. All rights reserved SSDI 0168.0072(93)E0084-2 ' See [3] for the classical approach to this question. * There is a general theorem by Lawvere of existence of left adjoints for algebraic functors which applies to our case. One may also directly use some adjoint functor theorem (see [17]). 3 This will be our trend for the rest of the paper: we give full details of the general theory and of its applications to the basic example of modal algebras,
more » ... hereas for the other cases we give only the final results. To get them from the general theorems one needs purely routine work, that can only be summarized here for evident reasons.
doi:10.1016/0168-0072(93)e0084-2 fatcat:cdebx4wvybdu7psf5fzct5kcoy