randRange(3, 8)
randRange(2, 4)
randFromArray([function(e,r){return["+",["*",C,e],r]},function(e,r){return["-",["*",C,e],r]},function(e,r){return["+",e,["*",C,r]]},function(e,r){return["-",e,["*",C,r]]},function(e,r){return["-",["*",C,e],["*",D,r]]},function(e,r){return["-",["*",D,e],["*",C,r]]},function(e,r){return["*",e,["-",r,C]]},function(e,r){return["*",["-",C,e],r]},function(e,r){return["+",["^",e,2],["*",D,["^",r,2]]]},function(e,r){return["+",["*",D,["^",e,2]],["^",r,2]]},function(e,r){return["-",["^",e,2],["*",D,["^",r,2]]]},function(e,r){return["-",["*",D,["^",e,2]],["^",r,2]]},function(e){return["-",["*",D,e],C]},function(e,r){return["+",["*",C,r],D]},function(e,r){return["+",["*",e,r],["*",D,e],["-",r]]}])
randRange(-6, 6)
randRange(-6, 6)
expr(FUN("x", "y"))
expr(FUN(X, Y))
expr(FUN(X, Y), true)
!isNaN(expr(FUN(0, NaN), true))
!isNaN(expr(FUN(NaN, 0), true))
Si x binop(1) y = TEXT, encuentra X binop(1) Y.
VALU
Sustituye en x = X y = Y x = X y y = Y para obetener SUBS.
Simplifica la expresión para obtener VALU.