[Bug]
>> a=-1.2
----------------------------
type: double
name: a
value: -1.2
--------------------
>> a
in> -1.2
out> -1.2
------------------------
>> -a
in> --1.2
hint> ===*=== syntax error ===*===
> It is not a valid expression.
> type `:help` to view some rules.
------------------------
>> -1*a
in> -1*-1.2
hint> ===*=== syntax error ===*===
> It is not a valid expression.
> type `:help` to view some rules.
------------------------
>> -1*(a)
in> -1*(-1.2)
out> 1.2
------------------------
>> a*(-1)
in> -1.2*(-1)
out> 1.2
------------------------