package fr.alnotz.quaternion; public interface IsQuaternion { double getS(); double getI(); double getJ(); double getK(); void setS(double s); void setI(double i); void setJ(double j); void setK(double k); IsQuaternion plus(IsQuaternion quaternion); IsQuaternion times(IsQuaternion quaternion); IsQuaternion conjugate(); boolean equals(IsQuaternion quaternion); String toString(); }