Add simple two-argument arithmetic coverage tests
Add simple two-argument arithmetic coverage tests

acenode/gambit,jasperla/gambit,BeImprovised/gambit,thewhimer/gambit,jasperla/gambit,thewhimer/gambit,BeImprovised/gambit,thewhimer/gambit,acenode/gambit,thewhimer/gambit,thewhimer/gambit,BeImprovised/gambit,acenode/gambit,jasperla/gambit,jasperla/gambit,acenode/gambit,BeImprovised/gambit,thewhimer/gambit