Consider the following adjusted relation schemas with primary keys in bold. All attributes are of

type string unless stated otherwise. For simplifying the construction of queries, utilize multi$-$step

and multi$-$line approaches.. Note that aggregate functions, as defined in some resources, are

not used here, as they are extensions beyond the classical Relational Model. PLEASE ONLY

USE RELATIONAL ALGEBRA ONLY. NO SQL COMMANDS ALLOWED!

Travelers$($TravelerID$,$ FirstName, LastName, TravelDocumentNumber, CountryOfOrigin$)$

Voyages$($VoyageID$,$ StartPoint, EndPoint, TakeoffTime, LandingTime, JourneyDate,

TransportID$)$

Passes$($PassID$,$ TravelerID, VoyageID, SeatingClass, Cost, AcquisitionDate$)$

Transports$($TransportID$,$ Model, Maker, SeatingCapacity$)$

Navigators$($NavigatorID$,$ FirstName, LastName, Position, ExperienceYears$)$

VoyageCrewLink$($VoyageID$,$ NavigatorID$)$

LeadTravelerLink$($VoyageID$,$ LeadID$)$

Mishaps$($MishapID$,$ VoyageID, OccurrenceDate, Spot, Summary$)$

Leads$($LeadID$,$ FullName, Seniority$)$

List all mishaps $($occurrence date, spot, and summary$)$ associated with LeadTravelerA $($distinct

name$).$

Determine which navigators $($first and last name$)$ have been part of the crew for every voyage

led by LeadTravelerA $($distinct name$).$

Identify all transports $($model and maker$)$ that have been accident$-$free to date.