Method nat_predicate_bool_result

crates/kernel/src/whnf.rs:2056–2071

(
    &mut self,
    decision: bool,
    args: &[KExpr<M>],
  )

        return Ok(None);
      },
    };

    let field_start = ctor_params;
    let Ok(field_idx) = usize::try_from(field) else {
      return Ok(None);
    };
    let idx = field_start + field_idx;
    let result = args.get(idx).cloned();
    self.dump_proj_trace(id, field, wval, Some(ctor_params), result.as_ref());
    Ok(result)
  }

  fn try_reduce_fin_val_decidable_rec(
    &mut self,
    id: &KId<M>,
    field: u64,
    head: &KExpr<M>,
    args: &[KExpr<M>],
  ) -> Option<KExpr<M>> {