Function semantic_jvp 

pub fn semantic_jvp(
    input: &FrozenProgram,
    active_inputs: &[bool],
    rules: &SemanticExtensionRuleSet,
) -> Result<SemanticAdProgram, SemanticAdTransformError>

Build a forward-mode derivative program.

active_inputs follows source-program input order. Each active input gets one appended tangent seed. The result maps source outputs to compact derivative-program outputs.

Errors

Returns SemanticAdTransformError::ActivityArity for a mask-length mismatch, SemanticAdTransformError::Extension for a rejected extension rule, or the corresponding Query, Build, Finish, or unsupported operation/metadata variant for failures encountered during transformation.