diff --git a/pystencils/assignment.py b/pystencils/assignment.py
index 92027f7773d2202765ab2ef09c5269654098060e..147a829f4d6698dc67ffd9a50a7b043c34064f9c 100644
--- a/pystencils/assignment.py
+++ b/pystencils/assignment.py
@@ -66,6 +66,7 @@ try:
     if int(sympy_version[0]) <= 1 and int(sympy_version[1]) <= 4:
         def hash_fun(self):
             return hash((self.lhs, self.rhs))
+
         Assignment.__hash__ = hash_fun
 except Exception:
     pass
@@ -94,16 +95,19 @@ def assignment_from_stencil(stencil_array, input_field, output_field,
         ...            [0, 6, 0]]
 
         By default 'visual ordering is used - i.e. the stencil is applied as the nested lists are written down
-        >>> assignment_from_stencil(stencil, f, g, order='visual')
-        Assignment(g_C, 3*f_W + 6*f_S + 4*f_C + 2*f_N + 5*f_E)
+        >>> expected_output = Assignment(g[0, 0], 3*f[-1, 0] + 6*f[0, -1] + 4*f[0, 0] + 2*f[0, 1] + 5*f[1, 0])
+        >>> assignment_from_stencil(stencil, f, g, order='visual') == expected_output
+        True
 
         'numpy' ordering uses the first coordinate of the stencil array for x offset, second for y offset etc.
-        >>> assignment_from_stencil(stencil, f, g, order='numpy')
-        Assignment(g_C, 2*f_W + 3*f_S + 4*f_C + 5*f_N + 6*f_E)
+        >>> expected_output = Assignment(g[0, 0], 2*f[-1, 0] + 3*f[0, -1] + 4*f[0, 0] + 5*f[0, 1] + 6*f[1, 0])
+        >>> assignment_from_stencil(stencil, f, g, order='numpy') == expected_output
+        True
 
         You can also pass field accesses to apply the stencil at an already shifted position:
-        >>> assignment_from_stencil(stencil, f[1, 0], g[2, 0])
-        Assignment(g_2E, 3*f_C + 6*f_SE + 4*f_E + 2*f_NE + 5*f_2E)
+        >>> expected_output = Assignment(g[2, 0], 3*f[0, 0] + 6*f[1, -1] + 4*f[1, 0] + 2*f[1, 1] + 5*f[2, 0])
+        >>> assignment_from_stencil(stencil, f[1, 0], g[2, 0]) == expected_output
+        True
     """
     from pystencils.field import Field
 
diff --git a/pystencils/fd/derivation.py b/pystencils/fd/derivation.py
index a2abc89c859fa9d6263ad66dbeab63b09a490bf5..e0e7a65ad31236f869ef287344ae52f3e3a7c528 100644
--- a/pystencils/fd/derivation.py
+++ b/pystencils/fd/derivation.py
@@ -1,5 +1,4 @@
 import itertools
-import warnings
 from collections import defaultdict
 
 import numpy as np
diff --git a/pystencils/fd/finitedifferences.py b/pystencils/fd/finitedifferences.py
index 5b6b15f95bebec40939d54a8ff2ad6c58c169f58..317e8e02537159e20a2c9ea75bc7cc308e1cb69e 100644
--- a/pystencils/fd/finitedifferences.py
+++ b/pystencils/fd/finitedifferences.py
@@ -21,10 +21,13 @@ def diffusion(scalar, diffusion_coeff, idx=None):
 
     Examples:
         >>> f = Field.create_generic('f', spatial_dimensions=2)
+        >>> d = sp.Symbol("d")
+        >>> dx = sp.Symbol("dx")
         >>> diffusion_term = diffusion(scalar=f, diffusion_coeff=sp.Symbol("d"))
         >>> discretization = Discretization2ndOrder()
-        >>> discretization(diffusion_term)
-        (f_W*d + f_S*d - 4*f_C*d + f_N*d + f_E*d)/dx**2
+        >>> expected_output = ((f[-1, 0] + f[0, -1] - 4*f[0, 0] + f[0, 1] + f[1, 0]) * d) / dx**2
+        >>> sp.simplify(discretization(diffusion_term) - expected_output)
+        0
     """
     if isinstance(scalar, Field):
         first_arg = scalar.center
@@ -313,8 +316,9 @@ def discretize_center(term, symbols_to_field_dict, dx, dim=3):
       >>> term
       x*x^Delta^0
       >>> f = Field.create_generic('f', spatial_dimensions=3)
-      >>> discretize_center(term, { x: f }, dx=1, dim=3)
-      f_C*(-f_W/2 + f_E/2)
+      >>> expected_output = f[0, 0, 0] * (-f[-1, 0, 0]/2 + f[1, 0, 0]/2)
+      >>> sp.simplify(discretize_center(term, { x: f }, dx=1, dim=3) - expected_output)
+      0
     """
     substitutions = {}
     for symbols, field in symbols_to_field_dict.items():
@@ -396,8 +400,10 @@ def discretize_divergence(vector_term, symbols_to_field_dict, dx):
         >>> x, dx = sp.symbols("x dx")
         >>> grad_x = grad(x, dim=3)
         >>> f = Field.create_generic('f', spatial_dimensions=3)
-        >>> sp.simplify(discretize_divergence(grad_x, {x : f}, dx))
-        (f_W + f_S + f_B - 6*f_C + f_T + f_N + f_E)/dx**2
+        >>> expected_output = (f[-1, 0, 0] + f[0, -1, 0] + f[0, 0, -1] -
+        ... 6*f[0, 0, 0] + f[0, 0, 1] + f[0, 1, 0] + f[1, 0, 0])/dx**2
+        >>> sp.simplify(discretize_divergence(grad_x, {x : f}, dx) - expected_output)
+        0
     """
     dim = len(vector_term)
     result = 0
diff --git a/pystencils_tests/test_fd_derivation.ipynb b/pystencils_tests/test_fd_derivation.ipynb
index 9bab8e1184ded88e63c74fff99a7f6596de2fbd0..4195e635454bca725cd4c235d008fca0a5fe1dd4 100644
--- a/pystencils_tests/test_fd_derivation.ipynb
+++ b/pystencils_tests/test_fd_derivation.ipynb
@@ -61,7 +61,7 @@
    "outputs": [
     {
      "data": {
-      "image/png": "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\n",
+      "image/png": "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\n",
       "text/latex": [
        "$\\displaystyle \\left[\\begin{matrix}0 & 0 & 0\\\\1 & -2 & 1\\\\0 & 0 & 0\\end{matrix}\\right]$"
       ],
@@ -123,7 +123,7 @@
    "outputs": [
     {
      "data": {
-      "image/png": "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\n",
+      "image/png": "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\n",
       "text/latex": [
        "$\\displaystyle \\left[\\begin{matrix}\\frac{1}{12} & - \\frac{1}{6} & \\frac{1}{12}\\\\\\frac{5}{6} & - \\frac{5}{3} & \\frac{5}{6}\\\\\\frac{1}{12} & - \\frac{1}{6} & \\frac{1}{12}\\end{matrix}\\right]$"
       ],
@@ -173,48 +173,8 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "expected_result = sp.Matrix([[1, -2, 1], [10, -20, 10], [1, -2, 1]]) / 12\n",
-    "assert expected_result[:] == isotropic_2d_00_res.as_array()[:]"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 9,
-   "metadata": {},
-   "outputs": [
-    {
-     "data": {
-      "text/plain": [
-       "sympy.tensor.array.dense_ndim_array.MutableDenseNDimArray"
-      ]
-     },
-     "execution_count": 9,
-     "metadata": {},
-     "output_type": "execute_result"
-    }
-   ],
-   "source": [
-    "type(isotropic_2d_00_res.as_array())"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 10,
-   "metadata": {},
-   "outputs": [
-    {
-     "data": {
-      "text/plain": [
-       "sympy.matrices.dense.MutableDenseMatrix"
-      ]
-     },
-     "execution_count": 10,
-     "metadata": {},
-     "output_type": "execute_result"
-    }
-   ],
-   "source": [
-    "type(expected_result)"
+    "expected_result = sp.Array([[1, -2, 1], [10, -20, 10], [1, -2, 1]]) / 12\n",
+    "assert expected_result == isotropic_2d_00_res.as_array()"
    ]
   },
   {
@@ -226,12 +186,12 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 11,
+   "execution_count": 9,
    "metadata": {},
    "outputs": [
     {
      "data": {
-      "image/png": "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\n",
+      "image/png": "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\n",
       "text/latex": [
        "$\\displaystyle \\left[\\begin{matrix}\\frac{1}{6} & \\frac{2}{3} & \\frac{1}{6}\\\\\\frac{2}{3} & - \\frac{10}{3} & \\frac{2}{3}\\\\\\frac{1}{6} & \\frac{2}{3} & \\frac{1}{6}\\end{matrix}\\right]$"
       ],
@@ -243,7 +203,7 @@
        "⎣1/6   2/3   1/6⎦"
       ]
      },
-     "execution_count": 11,
+     "execution_count": 9,
      "metadata": {},
      "output_type": "execute_result"
     }
@@ -257,12 +217,12 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 12,
+   "execution_count": 10,
    "metadata": {},
    "outputs": [],
    "source": [
-    "expected_result = sp.Matrix([[1, 4, 1], [4, -20, 4], [1, 4, 1]]) / 6\n",
-    "assert iso_laplacian[:] == expected_result[:]"
+    "expected_result = sp.Array([[1, 4, 1], [4, -20, 4], [1, 4, 1]]) / 6\n",
+    "assert iso_laplacian == expected_result"
    ]
   },
   {
@@ -274,7 +234,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 13,
+   "execution_count": 11,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -315,7 +275,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 14,
+   "execution_count": 12,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -345,7 +305,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 15,
+   "execution_count": 13,
    "metadata": {},
    "outputs": [
     {
@@ -369,7 +329,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 16,
+   "execution_count": 14,
    "metadata": {
     "pycharm": {
      "name": "#%%\n"
@@ -405,4 +365,4 @@
  },
  "nbformat": 4,
  "nbformat_minor": 2
-}
\ No newline at end of file
+}
diff --git a/pystencils_tests/test_sympy_optimizations.py b/pystencils_tests/test_sympy_optimizations.py
index b22ad9d7fb07c84b88388455b45e76f6b5decc3a..e33278b4fa529a9d577858ad63a03676c17dceb0 100644
--- a/pystencils_tests/test_sympy_optimizations.py
+++ b/pystencils_tests/test_sympy_optimizations.py
@@ -11,8 +11,11 @@ def test_sympy_optimizations():
         x, y, z = pystencils.fields('x, y, z:  float32[2d]')
 
         # Triggers Sympy's expm1 optimization
+        # Sympy's expm1 optimization is tedious to use and the behaviour is highly depended on the sympy version. In
+        # some cases the exp expression has to be encapsulated in brackets or multiplied with 1 or 1.0
+        # for sympy to work properly ...
         assignments = pystencils.AssignmentCollection({
-            x[0, 0]: sp.exp(y[0, 0]) - 1
+            x[0, 0]: 1.0 * (sp.exp(y[0, 0]) - 1)
         })
 
         assignments = optimize_assignments(assignments, optims_pystencils_cpu)
@@ -28,7 +31,7 @@ def test_evaluate_constant_terms():
     for target in ('cpu', 'gpu'):
         x, y, z = pystencils.fields('x, y, z:  float32[2d]')
 
-        # Triggers Sympy's expm1 optimization
+        # Triggers Sympy's cos optimization
         assignments = pystencils.AssignmentCollection({
             x[0, 0]: -sp.cos(1) + y[0, 0]
         })
@@ -53,8 +56,6 @@ def test_do_not_evaluate_constant_terms():
             x[0, 0]: -sp.cos(1) + y[0, 0]
         })
 
-        optimize_assignments(assignments, optimizations)
-
         ast = pystencils.create_kernel(assignments, target=target)
         code = pystencils.get_code_str(ast)
         assert 'cos(' in code