The `d A` (`calc-giac-language`

) command selects the
conventions of Giac, another free computer algebra system. The function
names in Giac are similar to Maxima. Complex numbers are written
‘`3 + 4 i`’. The standard special constants in Giac are the same as
in Calc, except that `infinity`

represents both Calc’s `inf`

and `uinf`

.

Underscores are allowed in function and variable names in Giac mode.
Brackets are used for subscripts. In Giac, indexing of lists begins at
0, instead of 1 as in Calc. So if ‘`A`’ represents the list
‘`[a,2,c,4]`’, then ‘`A[2]`’ would equal ‘`c`’. In general,
‘`A[n]`’ in Giac mode corresponds to ‘`A_(n+1)`’ in Normal mode.

The Giac interval notation ‘`2 .. 3`’ has no surrounding brackets;
Calc reads ‘`2 .. 3`’ as the closed interval ‘`[2 .. 3]`’ and
writes any kind of interval as ‘`2 .. 3`’. This means you cannot see
the difference between an open and a closed interval while in Giac mode.