(b) the restrictions in section 4 (a) above shall not apply to any information of disclosing party which
1. the receiving party possessed without such restrictions prior to receipt from the disclosing party
2. is disclosed to the receiving party by a source other than the disclosing party, which source is not under a confidentiality obligation with respect to the confidential information
3. is now or becomes publicly known (such as but not limited to, information disclosed in patents or publications) through no violation of this agreement
4. is independently developed by the receiving party after the date of this agreement without use of confidential information of the disclosing party, by persons who have not had access to confidential information
5. is released from the obligation of non-disclosure and use restriction in writing by the disclosing party