diff --git a/README.md b/README.md
index 5d23d467..0ea81047 100644
--- a/README.md
+++ b/README.md
@@ -3,6 +3,12 @@
 latex2sympy parses LaTeX math expressions and converts it into the
 equivalent SymPy form.
 
+## Requirements
+$ pip install antlr-python3-runtime  #for python3
+
+or 
+
+$ pip install antlr-python2-runtime #for python2
 ## Installation
 
 [ANTLR](http://www.antlr.org/) is used to generate the parser:
@@ -13,12 +19,12 @@ $ antlr4 PS.g4 -o gen
 
 ## Usage
 
-In Python 2.7:
+In Python 2.7 or 3.7:
 
 ```python
 from process_latex import process_sympy
 
-process_sympy("\\frac{d}{dx} x^{2}")
+process_sympy(r"\frac{d}{dx} x^{2}")
 # => "diff(x**(2), x)"
 ```
 
@@ -27,10 +33,10 @@ process_sympy("\\frac{d}{dx} x^{2}")
 |LaTeX|Image|Generated SymPy|
 |-----|-----|---------------|
 |`x^{3}`|![](https://latex.codecogs.com/gif.latex?%5CLARGE%20x%5E%7B3%7D)| `x**3`|
-|`\frac{d}{dx} |t|x`|![](https://latex.codecogs.com/gif.latex?%5CLARGE%20%5Cfrac%7Bd%7D%7Bdx%7D%20%7Ct%7Cx)|`Derivative(x*Abs(t), x)`|
+|`\frac{d}{dx} \|t\|x`|![](https://latex.codecogs.com/gif.latex?%5CLARGE%20%5Cfrac%7Bd%7D%7Bdx%7D%20%7Ct%7Cx)|`Derivative(x*Abs(t), x)`|
 |`\sum_{i = 1}^{n} i`|![](https://latex.codecogs.com/gif.latex?%5CLARGE%20%5Csum_%7Bi%20%3D%201%7D%5E%7Bn%7D%20i)|`Sum(i, (i, 1, n))`|
 |`\int_{a}^{b} \frac{dt}{t}`|![](https://latex.codecogs.com/gif.latex?%5CLARGE%20%5Cint_%7Ba%7D%5E%7Bb%7D%20%5Cfrac%7Bdt%7D%7Bt%7D)|`Integral(1/t, (t, a, b))`|
-|`(2x^3 - x + z)|_{x=3}`|![](https://latex.codecogs.com/gif.latex?%5CLARGE%20%282x%5E3%20-%20x%20+%20z%29%7C_%7Bx%3D3%7D)|`z + 51`
+|`(2x^3 - x + z)\|_{x=3}`|![](https://latex.codecogs.com/gif.latex?%5CLARGE%20%282x%5E3%20-%20x%20+%20z%29%7C_%7Bx%3D3%7D)|`z + 51`
 
 ## Contributing
 
diff --git a/process_latex.py b/process_latex.py
index 7c119d01..0eca9171 100644
--- a/process_latex.py
+++ b/process_latex.py
@@ -1,3 +1,4 @@
+from __future__ import print_function
 import sympy
 import antlr4
 from antlr4.error.ErrorListener import ErrorListener
@@ -497,22 +498,22 @@ def get_differential_var_str(text):
     return text
 
 def test_sympy():
-    print process_sympy("e^{(45 + 2)}")
-    print process_sympy("e + 5")
-    print process_sympy("5 + e")
-    print process_sympy("e")
-    print process_sympy("\\frac{dx}{dy} \\int y x^2 dy")
-    print process_sympy("\\frac{dx}{dy} 5")
-    print process_sympy("\\frac{d}{dx} \\int x^2 dx")
-    print process_sympy("\\frac{dx}{dy} \\int x^2 dx")
-    print process_sympy("\\frac{d}{dy} x^2 + x y = 0")
-    print process_sympy("\\frac{d}{dy} x^2 + x y = 2")
-    print process_sympy("\\frac{d x^3}{dy}")
-    print process_sympy("\\frac{d x^3}{dy} + x^3")
-    print process_sympy("\\int^{5x}_{2} x^2 dy")
-    print process_sympy("\\int_{5x}^{2} x^2 dx")
-    print process_sympy("\\int x^2 dx")
-    print process_sympy("2 4 5 - 2 3 1")
+    print(process_sympy("e^{(45 + 2)}"))
+    print(process_sympy("e + 5"))
+    print(process_sympy("5 + e"))
+    print(process_sympy("e"))
+    print(process_sympy("\\frac{dx}{dy} \\int y x^2 dy"))
+    print(process_sympy("\\frac{dx}{dy} 5"))
+    print(process_sympy("\\frac{d}{dx} \\int x^2 dx"))
+    print(process_sympy("\\frac{dx}{dy} \\int x^2 dx"))
+    print(process_sympy("\\frac{d}{dy} x^2 + x y = 0"))
+    print(process_sympy("\\frac{d}{dy} x^2 + x y = 2"))
+    print(process_sympy("\\frac{d x^3}{dy}"))
+    print(process_sympy("\\frac{d x^3}{dy} + x^3"))
+    print(process_sympy("\\int^{5x}_{2} x^2 dy"))
+    print(process_sympy("\\int_{5x}^{2} x^2 dx"))
+    print(process_sympy("\\int x^2 dx"))
+    print(process_sympy("2 4 5 - 2 3 1"))
 
 if __name__ == "__main__":
     test_sympy()