Expand Div

[oameye]

@syms a b c
expand((a + b)/c)

does not expand the division. Instead one can define

function expand_fraction(x::BasicSymbolic)
    @compactified x::BasicSymbolic begin
        Add => _apply_termwise(expand_fraction, x)
        Mul => _apply_termwise(expand_fraction, x)
        Div => sum([arg/x.den for arg in arguments(x.num)])
        _   => x
    end
end
expand_fraction(x::Num) = Num(expand_fraction(x.val))

"Apply a function f on every member of a sum or a product"
function _apply_termwise(f, x::BasicSymbolic)
    @compactified x::BasicSymbolic begin
        Add => sum([f(arg) for arg in arguments(x)])
        Mul => prod([f(arg) for arg in arguments(x)])
        Div => _apply_termwise(f, x.num) / _apply_termwise(f, x.den)
        _   => f(x)
    end
end

as a workaround.