ex: `\\begin{align*}
  \\frac{1}{\\lambda}\\, \\int_0^\\lambda \\eta^2\\; \\text{d}x
  &= \\frac{1}{\\lambda} \\int_0^\\lambda
          \\left\\{ \\eta_2 + H\\, \\operatorname{cn}^2 \\left(
              \\begin{array}{c|c} \\displaystyle \\frac{\\xi}{\\Delta} & m\\end{array}
          \\right) \\right\\}^2\\;
          \\text{d}\\xi
      = \\frac{H^2}{\\lambda} \\int_0^\\lambda
          \\operatorname{cn}^4 \\left( \\begin{array}{c|c} \\displaystyle \\frac{\\xi}{\\Delta} & m\\end{array} \\right)\\; \\te