It seems that you use "logical layer" here as a synonym to "logical perspective". I would stick to having consystent terminology.

Existing Wording:

For the logical layer, this specification defines a Unified Modeling Language (UML) model called the Expression Logical Model (ELM) that defines a canonical representation of expression logic.

Proposed Wording:

This perspective defines a Unified Modeling Language (UML) model called the Expression Logical Model (ELM) that defines a canonical representation of expression logic\.