Solution
= Solution
All entries must lie between zero and one. The tightest restriction comes from $p_{01}=\lambda$, so together with the given positivity the parameter range is
$$
\boxed{0<\lambda\leq1}.
$$
= Solution
All entries must lie between zero and one. The tightest restriction comes from $p_{01}=\lambda$, so together with the given positivity the parameter range is
$$
\boxed{0<\lambda\leq1}.
$$