injection

title

description

• a function $f:S\to T$ is “injective” if for every $t\in T$, there exists AT MOST one $s\in S$ such that $f(s)=t$
• one output is mapped to AT MOST one input
• prove:
  • assume $f(x_1)=f(x_2)$ for $x_1,x_2$ in S
  • show that this implies $x_1=x_2$