base (5)!(90)J
rule (x)J (0.6*x)F[!+(0.7*x)J<g(5)L>][!-(0.7*x)J<g(5)L>](0.3*x)J(0.4*x)FQ
rule (x)F (0.5*x)F(0.5*x)F
rule Q <r[(2)!(45)+F][(1)!(20)+F][(1)!F][(1)!(20)-F][(2)!(45)-F]>