@Override
    public boolean isOrdered() {
      return true;
    }

    @Override
    public boolean equals(@CheckForNull Object obj) {
      if (obj == this) {
        return true;
      }
      if (!(obj instanceof EndpointPair)) {
        return false;
      }

      EndpointPair<?> other = (EndpointPair<?>) obj;
      if (isOrdered() != other.isOrdered()) {
        return false;
      }

    @Override
    public boolean isOrdered() {
      return true;
    }

    @Override
    public boolean equals(@CheckForNull Object obj) {
      if (obj == this) {
        return true;
      }
      if (!(obj instanceof EndpointPair)) {
        return false;
      }

      EndpointPair<?> other = (EndpointPair<?>) obj;
      if (isOrdered() != other.isOrdered()) {
        return false;
      }

		if types.IsInt[et] || et == types.TIDEAL {
			okforeq[et] = true
			types.IsOrdered[et] = true
			okforarith[et] = true
			okforadd[et] = true
			okforand[et] = true
			ir.OKForConst[et] = true
			types.IsSimple[et] = true
		}

		if types.IsFloat[et] {
			okforeq[et] = true
			types.IsOrdered[et] = true
			okforadd[et] = true
			okforarith[et] = true
			ir.OKForConst[et] = true

    if (graph.isDirected()) {
      if (!endpointPair.isOrdered()) {
        return false;
      }

      Object source = endpointPair.source();
      Object target = endpointPair.target();
      return (node.equals(source) && graph.successors(node).contains(target))
          || (node.equals(target) && graph.predecessors(node).contains(source));
    } else {
      if (endpointPair.isOrdered()) {
        return false;
      }

    if (graph.isDirected()) {
      if (!endpointPair.isOrdered()) {
        return false;
      }

      Object source = endpointPair.source();
      Object target = endpointPair.target();
      return (node.equals(source) && graph.successors(node).contains(target))
          || (node.equals(target) && graph.predecessors(node).contains(source));
    } else {
      if (endpointPair.isOrdered()) {
        return false;
      }

type BasicInfo int

// Properties of basic types.
const (
	IsBoolean BasicInfo = 1 << iota
	IsInteger
	IsUnsigned
	IsFloat
	IsComplex
	IsString
	IsUntyped

	IsOrdered   = IsInteger | IsFloat | IsString
	IsNumeric   = IsInteger | IsFloat | IsComplex
	IsConstType = IsBoolean | IsNumeric | IsString
)

// A Basic represents a basic type.
type Basic struct {
	kind BasicKind

type BasicInfo int

// Properties of basic types.
const (
	IsBoolean BasicInfo = 1 << iota
	IsInteger
	IsUnsigned
	IsFloat
	IsComplex
	IsString
	IsUntyped

	IsOrdered   = IsInteger | IsFloat | IsString
	IsNumeric   = IsInteger | IsFloat | IsComplex
	IsConstType = IsBoolean | IsNumeric | IsString
)

// A Basic represents a basic type.
type Basic struct {
	kind BasicKind

  public void testIsOrdered() {
    assertFalse(numberOrdering.isOrdered(asList(5, 3, 0, 9)));
    assertFalse(numberOrdering.isOrdered(asList(0, 5, 3, 9)));
    assertTrue(numberOrdering.isOrdered(asList(0, 3, 5, 9)));
    assertTrue(numberOrdering.isOrdered(asList(0, 0, 3, 3)));
    assertTrue(numberOrdering.isOrdered(asList(0, 3)));
    assertTrue(numberOrdering.isOrdered(Collections.singleton(1)));

   * Returns {@code true} iff {@code endpoints}' ordering is compatible with the directionality of
   * this graph.
   */
  protected final boolean isOrderingCompatible(EndpointPair<?> endpoints) {
    return endpoints.isOrdered() == this.isDirected();
  }

  protected final <T> Set<T> nodeInvalidatableSet(Set<T> set, N node) {
    return InvalidatableSet.of(

   * Returns {@code true} iff {@code endpoints}' ordering is compatible with the directionality of
   * this graph.
   */
  protected final boolean isOrderingCompatible(EndpointPair<?> endpoints) {
    return endpoints.isOrdered() == this.isDirected();
  }

  protected final <T> Set<T> nodeInvalidatableSet(Set<T> set, N node) {
    return InvalidatableSet.of(