remark let's start with arithmetic kramer -1 2 sub show remark should be 3 kramer remark equality checking kramer 3 equal show remark should show true kramer pop count show remark should print 0, now stack has one element kramer 2 4 add 3 mul count show pop show remark first, prints 2, then the result 18 kramer remark lets check greater operation kramer 4 greater show pop pop remark stack should be empty now kramer remark string checking kramer quote habele quote gubele quote kumba quote kumba equal show true equal show remark equal for strings then for boolean comparison kramer clear remark remove all the stack contents kramer remark false or false should push false kramer quote fix quote und lessthan 2 4 equal or show remark false and false should push false kramer dup and show clear remark division of floats kramer 3.0 6.0 div show remark check also type conversion from float to integer kramer int show pop remark exchange kramer 5 10 exch sub 0 greater show clear remark should print 4 kramer 5 4 true ifelse show remark conversion to float from integer kramer float show remark boolean expected but float supplied .. so crashes kramer if