E.  (Verb)

MEMBER OF INTERVAL ( _ _ )  The ones in b=. x E. y indicate the beginning points of occurrences of the pattern x in y:

  	'co' E. 'cocoa'
1 0 1 0 0
	  (0 1 +/ i. 3) E. 4 | +/~ i. 5
1 0 0 0 0
0 0 0 0 0
0 0 1 0 0
0 1 0 0 0
0 0 0 0 0