Creates a new javafx.beans.binding.BooleanBinding that holds true if the value of a javafx.beans.value.ObservableNumberValue is equal to a constant value (with a tolerance).

Two operands a and b are considered equal if Math.abs(a-b) <= epsilon.

Allowing a small tolerance is recommended when comparing floating-point numbers because of rounding-errors.

Parameters:

op1		the constant value
op2		the ObservableNumberValue
epsilon		the permitted tolerance

Returns:  the new BooleanBinding

Exceptions:

NullPointerException

if the ObservableNumberValue is null