NB. Here are matrix functions for use in programs

 I=: =@i.@#	    NB. generate identity matrix using 1 I n
 inv=: %. 	    NB. matrix inverse
 mp=: +/ . *	NB. matrix product
 det=: -/ . *	NB. matrix determinant
 trans=: |:     NB. matrix transpose
 
 NB. here are some common APL functions

 do=: ".   NB. the do or execute function