(1) For all real numbers s1, s3, s4, l such that s1 ≤ s3 and s1 ≤ s4 and 0 ≤ l and l ≤ 1 holds s1 ≤ (1− l) · s3 + l · s4. (2) For all real numbers s1, s3, s4, l such that s3 ≤ s1 and s4 ≤ s1 and 0 ≤ l and l ≤ 1 holds (1− l) · s3 + l · s4 ≤ s1. (3) If n > 0, then mn mod m = 0. (4) If j > 0 and i mod j = 0, then i÷ j = j . (5) If n > 0, then in÷ i = in i . (6) If 0 < n and 1 < r, then 1 < rn. (7)...
