# Example for syside solver evaluate for the battery example has errors

**URL:** <https://forum.sensmetry.com/t/example-for-syside-solver-evaluate-for-the-battery-example-has-errors/589>\
**Category:** Bug Reports\
**Tags:** cli\
**Created:** [October 11, 2026, 7:57pm UTC](https://forum.sensmetry.com/t/example-for-syside-solver-evaluate-for-the-battery-example-has-errors/589 "2026-10-11T19:57:16Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![Richard\_Wallace](https://yyz2.discourse-cdn.com/flex008/user_avatar/forum.sensmetry.com/richard_wallace/32/307_2.png) [@Richard\_Wallace](https://forum.sensmetry.com/u/Richard_Wallace)\
**Post date:** [October 11, 2026, 7:57pm UTC](https://forum.sensmetry.com/t/example-for-syside-solver-evaluate-for-the-battery-example-has-errors/589/1 "2026-10-11T19:57:16Z")

</div>

For the battery.sysml example used in `syside solver evaluate` example on the [Evaluating possible values — Syside](https://docs.sensmetry.com/automator/solver/evaluate/) webpage. Values are produced that are not correct for SysML v2 syntax and datatypes.

Given (from the Sensmetry web page):

(Note the corrected naming notation for cellA & cell B voltage)

```auto
package Battery {
    private import ScalarValues::Integer;
    part def Cell {
        attribute voltage : Integer;
    }
    part battery [1] {
        part cellA : Cell [1] {
            attribute redefines voltage = 3;
        }
        part cellB : Cell [1];
        attribute totalVoltage = cellA.voltage + cellB.voltage;
    }
}

```

Using the syside solver evaluate command, the results are:

```auto
CMD> syside solver evaluate -i battery.sysml --expr "Battery::battery::totalVoltage" --max-values 3
{
  "result": {
    "subject": "Battery",
    "expression": "Battery::battery::totalVoltage",
    "determination": "undetermined",
    "outcome": {
      "shape": "attainable_set",
      "values": [
        {
          "value": "3/2",
          "witness": {
            "values": [
              ["Battery::Cell::voltage", "-3/2"],
              ["Battery::battery::cellA::voltage", "3"],
              ["Battery::battery::totalVoltage", "3/2"]
            ],
            "value": "3/2"
          }
        },
        {
          "value": "2",
          "witness": {
            "values": [
              ["Battery::Cell::voltage", "-1"],
              ["Battery::battery::cellA::voltage", "3"],
              ["Battery::battery::totalVoltage", "2"]
            ],
            "value": "2"
          }
        },
        {
          "value": "3",
          "witness": {
            "values": [
              ["Battery::Cell::voltage", "0"],
              ["Battery::battery::cellA::voltage", "3"],
              ["Battery::battery::totalVoltage", "3"]
            ],
            "value": "3"
          }
        }
      ],
      "exhaustive": "false"
    },
    "causes": [
      {
        "free_data": {
          "names": ["Battery::Cell::voltage"],
          "span": { "start_line": 4, "start_col": 9, "end_line": 4, "end_col": 37 }
        }
      }
    ]
  },
  "warnings": [],
  "exit_code": 0
}

```

The following errors occur for the witness values, as voltage is typed as an Integer, the values indicated as witness values are in error (An `Integer` specializes `Rational`, so every Integer is a Rational, but not the reverse. The number 3/2 is a Rational that is not an Integer, so it can’t be a value of an `Integer`-typed attribute.)

To make evaluate work, the specification has to be rewritten to have the correct syntax and typing. Note line 4 for the `default` or the “`:=`” operator and line 11 for explicit typing.

Corrected specification:

 ![image](https://canada1.discourse-cdn.com/flex008/uploads/syside/original/1X/a3e8f12fd7e02a1cfd467d9bf5445450658d3c05.png)

As written on the webpage, `evaluate` incorrectly attempts to override a binding feature value on line 8 for cellA.voltage, which should have been reported as an unknown value for cellB.voltage; hence, `evaluate` should have reported an invalid computation on line 11 (i.e., unknown result).

Given the corrected specification, evaluate reports valid witness values.

V/r,  
@Richard_Wallace

---

<div class="post-metadata">

**Author:** ![Adam\_Layne](https://yyz2.discourse-cdn.com/flex008/user_avatar/forum.sensmetry.com/adam_layne/32/230_2.png) [@Adam\_Layne](https://forum.sensmetry.com/u/Adam_Layne)\
**Post date:** [October 15, 2026, 12:20am UTC](https://forum.sensmetry.com/t/example-for-syside-solver-evaluate-for-the-battery-example-has-errors/589/2 "2026-10-15T00:20:47Z")

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Thanks for noticing this. It will be fixed in v1.0.0.

Adam Layne, PhD