make a graph with just nodes, one for each Ti
for each pair of operations across transactions {
    if (Ti and Tj have conflicting ops on variable X) {
        put a directed edge between Ti and Tj
            where the direction goes from
            first tx to access X to second tx to access X
        if this new edge forms a cycle in the graph
            return "Not conflict serializable"
    }
}
return "Conflict serializable"