Transform Erlang AST (M1) to MetaAST (M2).

This module implements the abstraction function α_Erlang that lifts Erlang-specific AST structures to the meta-level representation.

Erlang AST Patterns

Erlang uses a consistent tuple-based format:

• Literals: {type, line, value}
• Variables: {:var, line, name}
• Binary ops: {:op, line, op, left, right}
• Calls: {:call, line, func, args}

Metadata Preservation

The transformation preserves M1-specific information:

• :line - line number from source
• :erlang_form - original Erlang construct type