Equation Solver Python Script in GH for Mac

I am just stumbling through this, trying to stuff a Gaussian Elimination linear equation solver into the Python script component of GH (using WIP Rhino for Mac).  I get the error shown in picture (and copied at bottom).  The Gaussian Elimination script (included below the pict) works fine in Rhino-Python.

Any thoughts?

"""Provides a scripting component.
Inputs:
x: The x script variable
y: The y script variable
Output:
a: The a output variable"""

import rhinoscriptsyntax as rs

# Copyright (c) Isaac Evans 2011
# All rights reserved.

def myGauss(m):
# eliminate columns
for col in range(len(m[0])):
for row in range(col+1, len(m)):
r = [(rowValue * (-(m[row][col] / m[col][col]))) for rowValue in m[col]]
m[row] = [sum(pair) for pair in zip(m[row], r)]
# now backsolve by substitution
ans = []
m.reverse() # makes it easier to backsolve
for sol in range(len(m)):
if sol == 0:
ans.append(m[sol][-1] / m[sol][-2])
else:
inner = 0
# substitute in all known coefficients
for x in range(sol):
inner += (ans[x]*m[sol][-2-x])
# the equation is now reduced to ax + b = c form
# solve with (c - b) / a
ans.append((m[sol][-1]-inner)/m[sol][-sol-2])
ans.reverse()
return ans

##########################################################################
# Check to see if this file is being executed as the "main" python
# script instead of being used as a module by some other python script
# This allows us to use the module which ever way we want.

if( __name__ == "__main__" ):
#Call the function
a = myGauss(x)

ERROR MESSAGE:

{0;0}
0. Runtime error (ArgumentTypeException): __getitem__() takes exactly 2 arguments (1 given)

Traceback:
line 15, in myGauss, "<string>"
line 43, in script