# Methods common to all representations

Representations indicate the format of patterns in layers, and conversions between representations govern the content of connections between layers.

## description

    some_rep description

The description of `some_rep` additionally contains `Width`, and indication of the typical (or compulsory) width of associated patterns.

## find_conversion

    some_rep find_conversion source_rep

Return a conversion that converts patterns with representation `source_rep` to patterns with representation `some_rep`. If no current conversion exists, attempt:

1. Use the `force_conversion` mechanism for the subtype of `some_rep`. Most notably, this applies to blocked_representations, which will attempt to produce parallel_conversions if the number of blocks match, or if one end of the conversion has zero blocks, will change the number of blocks to match the opposite end.
2. Use any `conversion_solver` mechanisms that have been loaded. Most notably, `conversion_chain` loads one of these to create a `conversion_chain`.