“…The theories of Krein-Rutman [30] and Krasnosel'skiȋ [29] have been used by many authors to establish the existence of and then compare smallest eigenvalues of boundary value problems for differential equations [5,10,11,12,13,32], difference equations [7,16], dynamic equations on time scales [6,19], fractional differential equations [8,9,18,28], and delta fractional difference equations [17,33,34].…”