The Congruence Extension Property for fork extensions
George Grätzer · arXiv (Cornell University) · 2013
For a slim, planar, semimodular lattice, G. Czedli and E.\,T. Schmidt introduced the fork extension in 2012. In this note we prove that the fork extension has the Congruence Extension Property. This paper has been merged with Part II, under the title Congruences of fork extensions of slim semimodular lattices, see arXiv: 1307.8404