@Override
	public boolean equals(final Object obj) {
		return obj == this ||
			obj instanceof TRS<?> other &&
			_rules.equals(other._rules);
	}
Maps {@code this} TRS from type {@code V} to type {@code B}.

@param mapper the type mapper
@param <B> the target type
@return a new TRS for the mapped type
@throws NullPointerException if the {@code mapper} is {@code null}
jenetics.ext/src/main/java/io/jenetics/ext/rewriting/TRS.java