# Contents

## Idea

The notion of M-type is the formal dual of that of W-type: a certain coinductive type.

The categorical semantics of an $M$-type is a terminal coalgebra of an endofunctor.

## References

• Benno van den Berg, de Marchi Non-well-founded trees in categories, APAL 146 (2007) 40–59.

Last revised on October 4, 2012 at 23:53:53. See the history of this page for a list of all contributions to it.