No provision of this Agreement may be modified, waived or discharged unless such modification, waiver or discharge is approved by Employer’s Board or a Person authorized thereby and is agreed to in writing by Executive and, in the case of any such modification, waiver or discharge affecting the rights or obligations of GPHC, is approved by the Board of Directors of GPHC or a Person authorized thereby. No waiver by any party hereto at any time of any breach by any other party hereto of, or compliance with, any condition or provision of this Agreement to be performed by such other party shall be deemed a waiver of similar or dissimilar provisions or conditions at the same or at any prior or subsequent time. No waiver of any provision of this Agreement shall be implied from any course of dealing between or among the parties hereto or from any failure by any party hereto to assert its rights hereunder on any occasion or series of occasions.