<span class="keyword">val</span> substring_from_index : <a href="../../../IR/Exp/index.html#type-t">IR.Exp.t</a> <span>&#45;&gt;</span> <a href="../../../IR/Exp/index.html#type-t">IR.Exp.t</a> <span>&#45;&gt;</span> <a href="../../../BO/BufferOverrunUtils/ModelEnv/index.html#type-model_env">BO.BufferOverrunUtils.ModelEnv.model_env</a> <span>&#45;&gt;</span> <span>ret:<span class="type-var">'a</span></span> <span>&#45;&gt;</span> <a href="../../../BO/BufferOverrunDomain/Mem/index.html#type-t">BO.BufferOverru