```
from sympy import init_session
init_session()
a , mu, k, t = symbols('a, mu, k, t')
```

    IPython console for SymPy 0.7.6 (Python 2.7.6-64-bit) (ground types: python)
    
    These commands were executed:
    >>> from __future__ import division
    >>> from sympy import *
    >>> x, y, z, t = symbols('x y z t')
    >>> k, m, n = symbols('k m n', integer=True)
    >>> f, g, h = symbols('f g h', cls=Function)
    >>> init_printing()
    
    Documentation can be found at http://www.sympy.org


Given is a PDF of a Branching Erlang (or Coxian) Distribution. 


```
pdf = a * mu * exp(-mu*t)+ (((1-a)*(mu**k))/(factorial(k-1))) * (t**(k-1))*exp(-mu*t)
pdf
```


```
cdf = integrate(pdf, t)
cdf
```


```
eq = diff(cdf,t) - pdf
simplify(eq)
```


```

```
