System.Xml.Schema.SchemaCollectionCompiler.IsValidRestriction C# (CSharp) Method

        private bool IsValidRestriction(XmlSchemaParticle derivedParticle, XmlSchemaParticle baseParticle) {
            if (derivedParticle == baseParticle) {
                return true;
            }
            else if (derivedParticle == null || derivedParticle == XmlSchemaParticle.Empty) {
                return IsParticleEmptiable(baseParticle);
            }
            else if (baseParticle == null || baseParticle == XmlSchemaParticle.Empty) {
                return false;
            }
            if (baseParticle is XmlSchemaElement) {
                if (derivedParticle is XmlSchemaElement) {
                    return IsElementFromElement((XmlSchemaElement)derivedParticle, (XmlSchemaElement)baseParticle);
                }
                else {
                    return false;
                }
            }
            else if (baseParticle is XmlSchemaAny) {
                if (derivedParticle is XmlSchemaElement) {
                    return IsElementFromAny((XmlSchemaElement)derivedParticle, (XmlSchemaAny)baseParticle);
                }
                else if (derivedParticle is XmlSchemaAny) {
                    return IsAnyFromAny((XmlSchemaAny)derivedParticle, (XmlSchemaAny)baseParticle);
                }
                else {
                    return IsGroupBaseFromAny((XmlSchemaGroupBase)derivedParticle, (XmlSchemaAny)baseParticle);
                }
            }
            else if (baseParticle is XmlSchemaAll) {
                if (derivedParticle is XmlSchemaElement) {
                    return IsElementFromGroupBase((XmlSchemaElement)derivedParticle, (XmlSchemaGroupBase)baseParticle, true);
                }
                else if (derivedParticle is XmlSchemaAll) {
                    return IsGroupBaseFromGroupBase((XmlSchemaGroupBase)derivedParticle, (XmlSchemaGroupBase)baseParticle, true);
                }
                else if (derivedParticle is XmlSchemaSequence) {
                    return IsSequenceFromAll((XmlSchemaSequence)derivedParticle, (XmlSchemaAll)baseParticle);
                }
            }
            else if (baseParticle is XmlSchemaChoice ) {
                if (derivedParticle is XmlSchemaElement) {
                    return IsElementFromGroupBase((XmlSchemaElement)derivedParticle, (XmlSchemaGroupBase)baseParticle, false);
                }
                else if (derivedParticle is XmlSchemaChoice) {
                    return IsGroupBaseFromGroupBase((XmlSchemaGroupBase)derivedParticle, (XmlSchemaGroupBase)baseParticle, false);
                }
                else if (derivedParticle is XmlSchemaSequence) {
                    return IsSequenceFromChoice((XmlSchemaSequence)derivedParticle, (XmlSchemaChoice)baseParticle);
                }
            }
            else if (baseParticle is XmlSchemaSequence) {
                if (derivedParticle is XmlSchemaElement) {
                    return IsElementFromGroupBase((XmlSchemaElement)derivedParticle, (XmlSchemaGroupBase)baseParticle, true);
                }
                else if (derivedParticle is XmlSchemaSequence) {
                    return IsGroupBaseFromGroupBase((XmlSchemaGroupBase)derivedParticle, (XmlSchemaGroupBase)baseParticle, true);
                }
            }
            else {
                Debug.Assert(false);
            }

            return false;
        }