strange behavior of @take in Cadabra1.

Question

Hello,sometimes when I use @take(%) an error of node with different brackets on its children pops up. The next example shows that indeed there is a missing (round) bracket in the output:

suma:= A + B + C; exp:=@take[@(suma)]{1} + E; ( A + @(exp) ) + F;

The output is: (A + B + E + F;

any idea of whats going on? thank you in advance!

Answer 1

Any chance you can move to Cadabra 2? The options there are much more extensive, e.g. the version I just pushed to github can do

suma:= A + B + C;
exp = suma[1] + $E$;
other:= ( A + @(exp) ) + F;

which produces $A+B+E+F$ as expected. But you can also use Python slices, e.g.

suma:= A + B + C + D + E + F;
suma[1:4];

produces $B+C+D$. And so on.

Given the amount of spare time I have to work on Cadabra, I would rather spend it on version 2 than on fixing issues with version 1 which are already solved in version 2.