Add support for reverse.

[hzhangxyz]

No description provided.

[codecov]

Codecov Report

❌ Patch coverage is 12.50000% with 7 lines in your changes missing coverage. Please review.
✅ Project coverage is 37.56%. Comparing base (8f53b1b) to head (bb6f9c4).

Files with missing lines	Patch %	Lines
parity_tensor/parity_tensor.py	12.50%	7 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #29      +/-   ##
==========================================
- Coverage   38.57%   37.56%   -1.02%     
==========================================
  Files           3        3              
  Lines         197      205       +8     
  Branches       26       26              
==========================================
+ Hits           76       77       +1     
- Misses        121      128       +7     

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[codecov]

Codecov Report

❌ Patch coverage is 12.50000% with 7 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
grassmann_tensor/tensor.py	12.50%	7 Missing ⚠️

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[Copilot]

Pull Request Overview

This PR adds a new reverse method to the GrassmannTensor class that allows reversing specified indices while maintaining proper Grassmann algebra sign conventions.

• Implements tensor index reversal with automatic sign handling for Grassmann tensors
• Validates input indices for uniqueness and bounds checking
• Calculates and applies parity-based sign corrections according to Grassmann algebra rules

[Copilot]

[nitpick] The expression i in indices should be parenthesized for clarity. The current precedence could be confusing. Consider: arrow = tuple(self.arrow[i] ^ (i in indices) for i in range(self.tensor.dim()))

Suggested change

	arrow = tuple(self.arrow[i] ^ i in indices for i in range(self.tensor.dim()))
	arrow = tuple(self.arrow[i] ^ (i in indices) for i in range(self.tensor.dim()))

[Copilot]

[nitpick] The condition index in indices and self.arrow[index] should be parenthesized for clarity: (index in indices) and self.arrow[index]

Suggested change

	(self._unsqueeze(parity, index, self.tensor.dim()) for index, parity in enumerate(self.parity) if index in indices and self.arrow[index]),
	(self._unsqueeze(parity, index, self.tensor.dim()) for index, parity in enumerate(self.parity) if (index in indices and self.arrow[index])),