bracketlen

  
Purpose 		 
Return the length of the Lie bracket $x$.




Syntax 		 
l:=bracketlen(x);




Description 		 

This function also expects a pure bracket as posxinphb (see
simpLB below for the explanation of the pure bracket concept)
and returns the length, also known as order or depth of the Lie
bracket.  The length of any generator is one, for any other Lie
product $x$ it is the number of terms (operands) in the expansion of
$x$.





Arguments 		 
$x$  Some pure Lie bracket.




Examples 		 

Consider the PHB $B$, given in example for the function  phb in
p. .  Then the length of the third and twenty-second
elements of $B$ can be found as:
> l1:=bracketlen(B[3]);
> l2:=bracketlen(B[22]);
l1:=1
l2:=4





Notes 		 

This function is required by the phbize routine. It has been
provided to the user for his/her convenience, however it is unlikely that it
will really be needed.