Function expr_to_rust_static 

pub fn expr_to_rust_static(expr: &SpExpr) -> String

Convert an Assura Expr to a Rust expression for use in const context.

Compared to [expr_to_rust], this variant:

• Does not rename result to the compiler-generated result variable
• Does not emit i128::from() casts for numeric comparisons
• Does not translate Implies/In/NotIn/Concat to Rust idioms
• Emits quantifiers as /* forall ... */ true comments
• Passes old(expr) through as the inner expression
• Uses simplified match patterns (Ctor(..) instead of field bindings)