Solution
= Solution
<Continuity>[Continuity at a point] means: for every $\varepsilon>0$ there exists $\delta>0$ such that $d_X(x,x')<\delta$ implies $d_Y(f(x),f(x'))<\varepsilon$.
= Solution
<Continuity>[Continuity at a point] means: for every $\varepsilon>0$ there exists $\delta>0$ such that $d_X(x,x')<\delta$ implies $d_Y(f(x),f(x'))<\varepsilon$.