time of the special election, it did not negate the calling of such election, "indispensable to the elections validity." Since R.A. 6645 as amended "charges the voters with knowledge of this statutory notice and Comelec's failure to give the additional notice did not negate the calling of such special election, much less invalidate it", the court dismissed the petition for lack of merit and allowed the result of the election to stand. The "thirteenth" senator There had been four instances in the Fifth Republic where a seat was vacated exactly midway through the senators' term due to election to another office. In all cases, the thirteenth-placed senator in the immediately preceding election was not given the formers seat since the vacancy occurred after the election. In 1998, Senator Gloria Macapagal Arroyo was elected vice president midway through her term. Arroyo's seat was up for the 2001 election and no special elections were held, nor was the thirteenth-placed candidate during the 1998 Senate election (Roberto Pagdanganan) proclaimed winner. Later that year, Marcelo Fernan died in office, leaving two vacant seats in the Senate (Fernan's seat was also up in 2001). In 2004, Senator Noli de Castro was elected vice president midway through his term. De Castro's seat was up for the 2007 election and no special election was held, nor was the thirteenth-placed candidate during the 2004 Senate election (Robert Barbers) proclaimed winner. In 2007, Senator Alfredo Lim was elected mayor of Manila midway through his term. Lim's seat was up for the 2010 election and no special election was held, nor was the thirteenth-placed candidate during the 2007 Senate election (Koko Pimentel) proclaimed winner. On August 15, 2011, Pimentel assumed the seat of Juan Miguel Zubiri after allegations of electoral fraud. In 2010, Senator Benigno Aquino III was elected president midway through his term. Aquino's seat was up for the 2013 election and no special election was held, nor was the thirteenth-placed candidate during the 2010 Senate election (Risa Hontiveros) proclaimed winner. In all of those cases, the thirteenth-placed candidate was not given the vacant seat as the voters elected for only twelve senators. This was not a problem for senators elected from 1946 to 1971, as long as they were elected to a new position prior to the second Senate election of their terms; a senator is expected to see two Senate elections in a six-year term instead of