Multi-turn tool-use scenario.
Tools involved: VehicleControlAPI
MathAPI

User requests (one per turn):
user: I recently moved to San Francisco and I’m planning a trip to Rivermist. How far apart are these places? I'd like to gauge the distance before setting off on this adventure.
user: Now that I have the distance sorted, I'm considering the fuel situation. What's the current level of gasoline I have in liters?
user: With the liters in mind, I'll need to top up my vehicle’s tank. Please go ahead and fill up the tank before I hit the road.
user: As the journey is about to begin, could you kindly engage the 'START' ignition mode to ready the vehicle? I want to ensure everything's in perfect working order before I drive off.
user: Finally, I'm analyzing mileage statistics and need the logarithm of the distance to the base the previous fuel value, computed to a precision of 10. Use base of 20. This will help with assessing the fuel efficiency patterns.

Expected function call sequence:
VehicleControlAPI.gallon_to_liter
VehicleControlAPI.fillFuelTank
VehicleControlAPI.startEngine
VehicleControlAPI.get_zipcode_based_on_city
VehicleControlAPI.estimate_distance
MathAPI.logarithm