cythonを使っていてエラーが出ました

使うというかpyxファイルをビルドする時点でエラーを吐いてしまいました

以下に実行ファイルと実行結果を記します

expがおかしいようなのですが、どう改善していいかわかりません

ちなみに、1つのsetup.pyで複数のモジュールをビルドするには
どうすればよいでしょうか

よろしくお願いします

alpha.pyx

def alpha_z(to_all, to_user,t_user,t_all):
    a = exp(t_all + t_user) / (sum([exp(tall + tuser) for tall, tuser in zip(to_all, to_user)]))
    return a

----------------------------------------------------------
setup.py

# -*- coding: utf-8 -*-

from distutils.core import setup
from distutils.extension import Extension
from Cython.Distutils import build_ext

# for notes on compiler flags e.g. using
# export CFLAGS=-O2
# so gcc has -O2 passed (even though it doesn't make the code faster!)
# http://docs.python.org/install/index.html

ext_modules = [
    Extension( "alpha", ["alpha.pyx"] ),
]

setup(
    name = " alpha app" ,
    cmdclass={'build_ext': build_ext },
    ext_modules = ext_modules,
)

-------------------------------------------------------------------
実行結果

running build_ext
cythoning alpha.pyx to alpha.c

Error compiling Cython file:
------------------------------------------------------------
...
# -*- coding: utf-8 -*-

def alpha_z(to_all, to_user,t_user,t_all):
    """alpha a list using em_ST update rule"""
    a = exp(t_all + t_user) / (sum([exp(tall + tuser) for tall, tuser in zip(to_all, to_user)]))
          ^
------------------------------------------------------------

alpha.pyx:5:11: undeclared name not builtin: exp
building 'alpha' extension
C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\BIN\x86_amd64\cl.exe /c /nologo /Ox /W3 /GL /DNDEBUG /MD "-IC:\Users\AppData\Local\conda\conda\envs\anaconda\include" "-IC:\Users\AppData\Local\conda\conda\envs\anaconda\include" "-IC:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\INCLUDE" "-IC:\Program Files (x86)\Windows Kits\10\include\10.0.10240.0\ucrt" "-IC:\Program Files (x86)\Windows Kits\10\include\10.0.10240.0\shared" "-IC:\Program Files (x86)\Windows Kits\10\include\10.0.10240.0\um" "-IC:\Program Files (x86)\Windows Kits\10\include\10.0.10240.0\winrt" /Tcalpha.c /Fobuild\temp.win-amd64-3.6\Release\alpha.obj
alpha.c
alpha.c(1): fatal error C1189: #error:  Do not use this file, it is the result of a failed Cython compilation.
error: command 'C:\\Program Files (x86)\\Microsoft Visual Studio 14.0\\VC\\BIN\\x86_amd64\\cl.exe' failed with exit status 2