The author would like to correct some text in the article above:
Page 4, line 24:-
Assumption 1 (Downward trade-off). For any triple $O_{i-1}$ , $O_i$ , $O_{i+1} \in {\bf O}$ and for any $p \in (0, 1)$ , there is a $q \in (0,1)$ such that:
Should read:-
Assumption 1 (Downward trade-off). For any triple $O_{j-1}$ , $O_j$ , $O_i \in {\bf {\it O}}$ , where $j < i$ , and for any $p \in (0, 1)$ , there is a $q \in (0, 1)$ such that:
Page 6, line 16:-
Assumption 2 (Upward trade-off). For any triple $O_{j-1}$ , $O_j$ , $O_{j+1} \in {\bf {\it O}}$ and for any $p \in (0, 1)$ , there is a $q \in (0, 1)$ such that:
Should read:-
Assumption 2 (Upward trade-off). For any triple $O_j$ , $O_i$ , $O_{i+1} \in {\bf {\it O}}$ , where $j < i$ , and for any $p \in (0, 1)$ , there is a $q \in (0, 1)$ such that:
The author would like to apologize for this error.