| a b c d min max epsilon x1 valuex valuemin |
a := 1.
b := 4.
c := 3.
min := -2.
max := 2.
epsilon := 0.0001.

d := (b * b) - (4 * a * c).

[ (max - min) > epsilon ] whileTrue:
    [   x1 := (max + min) / 2.
        valuex := (a * x1 * x1) + (b * x1) + c.
        valuemin := (a * min * min) + (b * min) + c.
        valuex < 0
            ifTrue: [ valuex := valuex * (-1)].
        valuex < epsilon
            ifTrue: [^Transcript show: (x1 asString); cr.]
            ifFalse: [(valuex * valuemin) < 0
                ifTrue: [max := x1]
                ifFalse: [min := x1]
            ]
    ]