Method operator-

src/script/script.h:287–293

        return CScriptNum(result);
    }
    inline CScriptNum operator-(const int64_t &rhs) const {
        int64_t result;
        if (SubInt63Overflow(m_value, rhs, result)) {
            throw scriptnum_overflow_error("script number overflow");
        }
        return CScriptNum(result);
    }
    inline CScriptNum operator+(const CScriptNum &rhs) const {
        return operator+(rhs.m_value);
    }