Round 1 of changes

pymbolic/geometric_algebra/mapper.py

pymbolic/imperative/transform.py

pymbolic/interop/ast.py

pymbolic/interop/common.py

pymbolic/interop/sympy.py

pymbolic/mapper/__init__.py

pymbolic/mapper/constant_folder.py

pymbolic/mapper/differentiator.py

pymbolic/mapper/unifier.py

pymbolic/parser.py

pymbolic/polynomial.py

pymbolic/primitives.py