[Feature]: `SoftDot` node documentation and test

[wouterwln]

Parent Epic

#554

Feature Summary

Provide derivations for the rules in the SoftDot node and improve the quality of the test suite.

Feature Description

The SoftDot node has an undocumented functional form, the rules are not straightforward and not documented either in the Overleaf file or in the repository. Furthermore, the tests are extremely barebones and do not test actual functionality, providing

Feature Goals

• Document rule derivations
• Improve test suite for all rules
• Improve performance of rules

Tasks

• Add SoftDot rules for x to overleaf
• Add SoftDot rules for y to overleaf
• Add SoftDot rules for gamma to overleaf
• Add SoftDot rules for theta to overleaf
• Add tests for x
• Add tests for y
• Add tests for gamma
• Add tests for theta

Dependencies

No response

Estimated Timeline

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Related Issues / PRs

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Additional Context

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