Full Idea
Of the equivalence relationships which occur between patterns, congruence is the strongest, equivalence the next, and mutual occurrence the weakest. None of these is identity, which would require the same position.
Clarification
'Congruence' is identity of shape
Gist of Idea
Congruence is the strongest relationship of patterns, equivalence comes next, and mutual occurrence is the weakest
Source
Michael D. Resnik (Maths as a Science of Patterns [1997], Three.10.3)
Book Reference
Resnik,Michael D.: 'Mathematics as a Science of Patterns' [OUP 1999], p.209
A Reaction
This gives some indication of how an account of mathematics as a science of patterns might be built up. Presumably the recognition of these 'degrees of strength' cannot be straightforward observation, but will need an a priori component?