J = -k * grad(phi)
F = k * Q1 * Q2 / r^2
d2x/dt2 = -omega^2 x
dQ/dt = -Q/tau
d2u/dt2 = c^2 * laplacian(u)
du/dt = D * laplacian(u)
dP/dt = r P (1 - P/K)
sum(in) = sum(out) + d(store)/dt
S = -k * sum(p_i log p_i)
delta(integral L) = 0
f(t) = sum c_n e^(i n omega t)
L = k * log10(x / x_ref)
p(x) ~ e^(-(x-mu)^2 / (2 sigma^2))
laplacian(phi) = -rho / k
n ~ e^(-E / kT)
dy/dt = k y
V = (RT / zF) * ln(C_out / C_in)
dx_i/dt = x_i (f_i - <f>)
pi = pi P (pi P = pi)
S = a / (1 - r), |r| < 1
Gamma = (Z2 - Z1) / (Z2 + Z1)
y = 1 / (1 + e^(-x))
V*(s) = max_a [ R(s,a) + gamma * sum_s' P(s'|s,a) V*(s') ]