| 02B0AB | ~xHEAD | ( {} → ob )
 (  $ → $' )First Listed Element Cmd
 
 --Returns the first element of a
list or string.
 
 --Related: TAIL
 | 
| 0010AB | ~xLININ | ( symb var → 0/1 )Linear Test Func
 
 --Tests whether an algebraic is
structurally linear for a given
variable.
 | 
| 00F0AB | ~xLQ | ( [[]] → [[L]] [[Q]] [[P]] )LQ Factorization of a Matrix Cmd
 
 --Returns the LQ factorization of
an n×m matrix.
 
 --Related: LSQ,QR
 | 
| 0080AB | ~xLSQ | (   [B] [[A]] → []'   )
 ( [[B]] [[A]] → [[]]' )Least Squares Solution Cmd
 
 --Returns the minimum norm least
squares solution to any system of
linear equations where A × X = B
 
 --Related: LQ,RANK,QR,/
 | 
| 00D0AB | ~xLU | ( [[]] → [[L]] [[U]] [[P]] )LU Dec of a Sq. Matrix Cmd
 
 --Returns the LU decomposition of a square
matrix.
 
 --Related: DET,INV,LSQ,/
 | 
| 0280AB | ~xMSGBOX | ( $ →  )Message Box Cmd
 
 --Creates a user-defined message
box.
 
 --Related: CHOOSE,INFORM,PROMPT
 |