Problem Statement

(Given an equal-probability generator of one of the integers 1 to 5 as dice5),   create dice7 that generates a pseudo-random integer from 1 to 7 in equal probability using only dice5 as a source of random numbers,   and check the distribution for at least one million calls using the function created in   Simple Random Distribution Checker.

Implementation suggestion: dice7 might call dice5 twice, re-call if four of the 25 combinations are given, otherwise split the other 21 combinations into 7 groups of three, and return the group index from the rolls. (Task adapted from an answer here)

Let's start with the solution:

Procedure dice5()
  ProcedureReturn Random(4) + 1
EndProcedure
 
Procedure dice7()
  Protected x
  
  x = dice5() * 5 + dice5() - 6
  If x > 20 
    ProcedureReturn dice7()
  EndIf 
  
  ProcedureReturn x % 7 + 1
EndProcedure