+ [[trunc(5.06, .1)], [5.00]],
+ [[trunc(-5.06, .1)], [-5.00]],
+ [[trunc(1)], [1.00]],
+ [[trunc(1 - 2**-53)], [1.00]],
+ [[trunc(1 - 2**-52)], [1.00]],
+ [[trunc(1 - 2**-51)], [1.00]],
+ [[trunc(1 - 2**-45)], [0.00]],
+ [[trunc(1 - 2**-45, 1, 10)], [1.00]],