Catecon Blog October 21, 2018

Factor Morphisms

In Catecon a factor morphism is derived from a product domain by listing indices giving factors in the the product hierarchy.  This then forms various projections and deltas from the given domain to the codomain.

For example, suppose you have a domain of AxBxC, and you want to make two copies of A, drop B, and keep C.  The indices giving the factor morphism are thus [0], [0], [2] where the integer refers to the factor position in the product.

Recent work has been in getting the indices and string morphisms correct, such as when terminal objects are inserted into the codomain and when the domain is a complex hierarchy of products.  The Factor Morphisms diagram was created to show examples and do basic tests of such morphisms.


Copy Objects

A morphism is easily copied with control-drag, but control-drag on an object creates an identity.  Now the toolbar shows a copy object icon for objects selected in an editable diagram.

Shift-Click Products and Coproducts to Keep Originals

When you select some objects or select some morphism, the toolbar gives you choice of forming a product or coproduct.  If you just click the product or coproduct button, then the new element is formed at the barycenter of the selected elements and the components are decremented by one reference count that may remove them from the diagram.

But if you shift-click, the component elements are not decremented and so stay on the diagram.

Preview Area

To make it easier to preview the uploaded diagram snapshot, the settings panel has a means for turning on such a feature.


The help facility has been broken down into a method per class instead of one method for all.  This improves the quality of help per class.

String Coloring

The string morphism coloring is updated to a twelve color wheel versus the prior random coloring.