Hello I am interested in how to pass stdout twice to the same command...

For instance, If I run the following:

```
seq 5 >a
tac a >b
paste a b

```

then I get:

```
1       5
2       4
3       3
4       2
5       1

```

The following also deliver the same result:

```
paste <(seq 5) <(seq 5 |tac)

```

or

```
seq 5 | paste - <(seq 5 |tac)

```

I want to use `seq 5` only once - perhaps similar to these attempts, which do not work:

```
seq 5 | paste - <(tac -)

```

or

```
seq 5 | tee >(tac 1>&3) | paste - >(3>&1 cat)

```

I expect some kind of file descriptor manipulation or further process substitution magic will do the trick but I am having trouble getting there.