title: 'SYMBOL' object is not callable
body: <p>this is my first time with sympy and I don't know what I'm doing wrong. Could you help me please?</p>
  
  <p>This is my code:</p>
  
  <pre><code>from __future__ import division
  from sympy import *
  
  q, l, p = symbols('q, l, p')
  x1, x2, x3, x4, x5, x6, x7 = symbols('x1, x2, x3, x4, x5, x6, x7')
  c1, c2, c3, c4, c5, c6, c7 = symbols('c1, c2, c3, c4, c5, c6, c7')
  c8, c9, c10, c11, c12, c13, c14 = symbols('c8, c9, c10, c11, c12, c13, c14')
  
  
  a = 209 * q * l / 42 - p / 3
  "TRECHO AB"
  m1 = a * x1 - q * x1 ** 2 / 2
  d1 = integrate(m1, x1) + c1
  y1 = integrate(d1, x1) + c2
  
  "TRECHO BC"
  m2 = a * 2 * l + a * x2 - 2 * q * l(x2 + l)
  d2 = integrate(m2, x2) + c3
  y2 = integrate(d2, x2) + c4
  
  "TRECHO CD"
  m3 = a(3 * l + x3) - 2 * q * l(2 * l + x3) - q * x3 ** 3 / 6 * l
  d3 = integrate(m3, x3) + c5
  y3 = integrate(d3, x3) + c6
  
  "TRECHO DE"
  m4 = a(x4 + 6 * l) - 2 * q * l(x4 + 5 * l) - (9 * q * l / 2)(x4 + l)
  d4 = integrate(m4, x4) + c7
  y4 = integrate(d3, x4) + c8
  
  "TRECHO FG"
  m5 = a(x5 + 7 * l) - 2 * q * l(x5 + 6 * l) - (9 * q * l / 2)(x5 + 2 * l) - p * x5
  d5 = integrate(m5, x5) + c9
  y5 = integrate(d5, x5) + c10
  
  "TRECHO GH"
  m6 = a(x6 + 15 * l / 2) - 2 * q * l(x6 + 13 * l / 2) - (9 * q * l / 2)(x6 + 5 * l / 2) - p(x6 + l / 2) - 2 * q * x6(
      x6 / 2)
  d6 = integrate(m6, x6) + c11
  y6 = integrate(d6, x6) + c12
  
  "TRECHO HI"
  m7 = a(x7 + 19 * l / 2) - 2 * q * l(x7 + 17 * l / 2) - (9 * q * l / 2)(x7 + 9 * l / 2) - p(x7 + 5 * l / 2) - 4 * q * l(
      x7 + l) - (3 * q * x7 ** 2 / 2 * l)(x7 / 3)
  d7 = integrate(m7, x7) + c13
  y7 = integrate(d7, x7) + c14
  
  print(
      "{},\n{},\n{},\n{},\n{},\n{},\n{},\n{},\n{},\n{},\n{},\n{},\n{},\n{}".format(d1, y1, d2, y2, d3, y3, d4, y4, d5, y5,
                                                                                   d6, y6, d7, y7))
  </code></pre>
  
  <p>The traceback:</p>
  
  <pre><code>Traceback (most recent call last):
    File "mecsolidos2.py", line 17, in &lt;module&gt;
      m2 = a * 2 * l + a * x2 - 2 * q * l(x2 + l)
  TypeError: 'Symbol' object is not callable
  </code></pre>
  
  <p>That is the same error to m3 through m7 :S
  I've tried to change m2 to another constant, used m2 as m2.eval but none of that worked :S
  What pissed me of was that for m1 it worked perfectly</p>
  
  <p>ps: sorry for my bad english</p>