Extract a decimal from a vector in maple

Question

Not sure if this question belongs in this form but I don't know where else to go. I'm trying to index a matrix and do a < comparison on it. Every time I try something like A[1] it says:

Error, a Vector is not valid lhs to < or <=.

Can anyone help?

EXAMPLE:

A:=<1,2,3>:

b:=A[2]:

if b < 2 then .....

Answer 1

Which version of Maple are you using? For me, using Maple 12, the following works just fine:

A := <1,2,3>;

$$A := \begin{bmatrix}1 \\ 2 \\ 3\end{bmatrix}$$

b := A[2];

$$b := 2$$

is(b < 2);

$$false$$

is(b <= 2);

$$true$$