\(h\left( {t,s} \right) = 0.3{\left( {1 - t} \right)^2}{e^{ - {t^2} - {{\left( {s + 1} \right)}^2}}} - \left( {0.2t - {t^3} - {s^5}} \right){e^{ - {t^2} - {s^2}}} - 0.1{e^{ - {{\left( {t + 1} \right)}^2} - {s^2}}}\)