This excerpt taken from the SNPS 10-Q filed Mar 9, 2006.
10. EXECUTION OF DOCUMENTS. You hereby acknowledge and agree that the manner selected by the Corporation by which you indicate your consent to your Grant Notice is also deemed to be your execution of your Grant Notice and of this Agreement. You further agree that such manner of indicating consent may be relied upon as your signature for establishing your execution of any documents to be executed in the future in connection with your Annual Award.