Revert "Merge branch 'uneval' into 'master'"

This reverts merge request !63

sumpy/expansion/multipole.py

@@ -178,11 +178,11 @@ class VolumeTaylorMultipoleExpansionBase(MultipoleExpansionBase):
                     assert n >= k
                     from sympy import binomial
                     contrib *= (binomial(n, k)
-                            * sym.UnevaluatedExpr(dvec[idim]/tgt_rscale)**(n-k))
+                            * dvec[idim]**(n-k))
 
                 result[i] += (
                         contrib
-                        * sym.UnevaluatedExpr(src_rscale/tgt_rscale)**sum(src_mi))
+                        * (src_rscale**sum(src_mi) / tgt_rscale**sum(tgt_mi)))
 
             result[i] /= mi_factorial(tgt_mi)
 

sumpy/symbolic.py

@@ -98,19 +98,6 @@ def _coeff_isneg(a):
     return a.is_Number and a.is_negative
 
 
-have_unevaluated_expr = False
-if not USE_SYMENGINE:
-    try:
-        from sympy import UnevaluatedExpr
-        have_unevaluated_expr = True
-    except ImportError:
-        pass
-
-if not have_unevaluated_expr:
-    def UnevaluatedExpr(x):  # noqa
-        return x
-
-
 # {{{ debugging of sympy CSE via Maxima
 
 class _DerivativeKiller(IdentityMapperBase):