Continuous time Voltage adder/subtractor circuit -- Help

[fredflinstone]

voltage subtractor circuit

Hi alll,
I am in search of a continuous time voltage adder /subtractor circuit . I know that we can implement subtraction/addition using switched capacitor configurations.
Please help me if u know any such circuits iimplementable in MOS.

thanks in advance
fred

 

[sunking]

switched capacitor circuit as subtractor

why not use opa and res directory?