OLYMPIA — The state Supreme Court is weighing arguments over legislative action in recent years to end some pension benefit increases for state and local government employees.At issue are two actions taken by lawmakers. In 2007, the Legislature repealed pension “gain-sharing” that benefited retirees when the markets were doing well. Then in 2011, lawmakers ended cost-of-living increases for pensions for former state employees enrolled in two older pension plans. Lawsuits were filed by various unions that opposed the changes, including the Washington Federation of State Employees. The high court heard both cases Thursday.In 2010, a King County judge ruled that lawmakers violated contractual rights by taking away gain-sharing without providing comparable replacement benefits. And last year, a Thurston County judge ruled that the Legislature was wrong to eliminate the annual increase in benefits to retirees.