V, t, b, L = symbols("V, t, b, L")
L_array = [5, 10, 15, 20, 25]
b_val = 0.0032
expr = b * V * 0.277 * t - b * L - log(1 + b * V * 0.277 * t)
expr_list = [expr.subs({b: b_val, L: L_val}) for L_val in L_array]
labels = ["L = %s" % L_val for L_val in L_array]
plot_implicit(*expr_list, (t, 0, 3), (V, 0, 1000), label=labels)
# Expected:
## Plot object containing:
## [0]: Implicit expression: Eq(0.0008864*V*t - log(0.0008864*V*t + 1) - 0.016, 0) for t over (0, 3) and V over (0, 1000)
## [1]: Implicit expression: Eq(0.0008864*V*t - log(0.0008864*V*t + 1) - 0.032, 0) for t over (0, 3) and V over (0, 1000)
## [2]: Implicit expression: Eq(0.0008864*V*t - log(0.0008864*V*t + 1) - 0.048, 0) for t over (0, 3) and V over (0, 1000)
## [3]: Implicit expression: Eq(0.0008864*V*t - log(0.0008864*V*t + 1) - 0.064, 0) for t over (0, 3) and V over (0, 1000)
## [4]: Implicit expression: Eq(0.0008864*V*t - log(0.0008864*V*t + 1) - 0.08, 0) for t over (0, 3) and V over (0, 1000)