Let $\mathcal{B}(\mathbb{R})$ be the D5315: Standard real borel sigma-algebra.
Let $\{ W_t \}_{t \in [0, \infty)}$ be a D3658: Standard real Wiener process.
A D5076: Random real process $B : [0, 1] \to \text{Random}(\Omega \to \mathbb{R})$ is a standard real brownian bridge process if and only if
\begin{equation}
\forall \, t \in [0, 1] :
\forall \, E \in \mathcal{B}(\mathbb{R}) :
\mathbb{P}(B_t \in E)
= \mathbb{P}(W_t \in E \mid W_1 = 0)
\end{equation}