MATEN Forms can be hierarchized, organized in a Graph data structure.
This means that instead of reaching a 'zero state' before invoking new Form, we can invoke an 'Intermediary Form' that is 'closer' to the 'empty form' (or zero state), but not quite it. Then proceed with invoking Form available from that 'Intermediary Form'.
There can be any number of more or less 'Extended' Forms, and 'Intermediary' Forms in between. Each of such can be goal of reducing or extending step. Extended MATEN can go through any number of steps during reduction and through any number of steps during extension phases.
There can be restrictions on Graph's shape and rules of traversal between nodes on such Graph. For example: 'up' or 'down' only, with 'shared nodes' between paths.
See also: More about 'Ola AH' Language (background).