Mutual Form is a structure: it formalizes and stabilizes the relational dynamics between distinct multi-relational units.
Given that the conditions of Mutual Relation and Field Coherence are determined by how they structure the interplay between differentiated units and the broader relational field, it cannot not derive twin structures: Mutual Form and Field Form.
Mutual Form formalizes the local dynamics: how distinct units relate across their Boundarys while preserving their differentiation. It is the structural counterpart to Mutual Relation, just as Relational Form (step 2) formalized the interplay of Relating and Relation.