A typo, sorry.

> Expected output:
>
> /cca/rela(1)/fa   10
> /cca/rela(1)/fc(1)/fc_fa   Y1
> /cca/rela(5)/fa   50
> /cca/rela(5)/fb   51                       ------------------- not .../fa
> /cca/rela(5)/fc(1)/fc_fb   51
> /cca/rela(5)/fc(2)/fc_fa   A2
> /cca/rela(5)/fc(2)/fc_fb   52
>
> Note that parentheses enclose values of @_ix.