package org.activityinfo.model.expr.functions; import org.activityinfo.model.type.number.Quantity; import java.util.Objects; class MinusFunction extends RealValuedBinaryFunction { public MinusFunction() { super("-"); } @Override protected double apply(double a, double b) { return a - b; } @Override protected String applyUnits(String a, String b) { if(Objects.equals(a, b)) { return a; } else { return Quantity.UNKNOWN_UNITS; } } }