SOL is the sole medium with which blockspace can be purchased within the Solana network (i.e., the only medium in which transaction fees are paid).

SOL is the sole medium with which blockspace can be purchased within the Solana network (i.e., the only medium in which transaction fees are paid).
[1] = ƒ(blockspaceDemand, feeMarketPressure)
blockspaceDemand
— measurement of the computational resources required to process transactions (directly tied to ETH's exchange utility)feeMarketPressure
— an abstract reflection of the competitive dynamics of transaction fee bidding (a direct value transfer mechanism)Like Ethereum, Solana has base and priority fees. Unlike Ethereum, Solana's base fee is fixed at 5000 lamports per signature included in the transaction, and only half thereof is burned. Regardless, this also engenders a consistent appreciation of SOL due to deflation. Please note that the deflation rate need not necessarily exceed the inflation rate for its effect to be observable, at least as a slowdown of depreciation.
[21] = ƒ(token_extant, token_burnt, token_generated)
token_extant
— the amount of SOL in existencetoken_burnt
— the amount of SOL burnt in a given timeframetoken_generated
— the amount of SOL minted in a given timeframeSolana does not presently have automatic slashing nor, strictly speaking, a minimal SOL requirement. However, in order to participate in consensus, a vote account is required, which must have a rent-exempt reserve of 0.02685864 SOL. In addition, staking increases the weight of a delegator, which gives it preferential treatment in selection of validators for tx processing. As with other staking mechanisms, despite the lack of automated slashing, staking is still engendering the impacted tokens due to the mandated immobilisation periods.
[7] = ƒ(staking_period, amount_staked, price_at_staking)
staking_period
— the duration of the lock-up periodamount_staked
— the amount of tokens locked up by the userprice_at_staking
— the price of the locked token position at the moment of locking; defines the locked value together with the lockedOnce a validator is set up, he must also participate in the consensus to qualify for remuneration.
[81] = binary
Reflects rewards earned by validators. When a validator performs his duties correctly, he is eligible to receive a number of rewards:
[22] = ƒ([81], fee_income, consensus_reward_parameters)
fee_income
— the variable fee income of a validatorconsensus_reward_parameters
— the parameters of the consensus reward emissionsA staker of SOL need not run a validator himself; rather, he may choose to delegate his stake to any other validator. This delegated stake counts towards the validator's for the purposes of determining his stake weight, but the question of slashing this stake is absent because automatic slashing is not enshrined in the design of Solana, unlike token delegation.
[82] = ƒ([7], validator_params)
validator_params
— the parameters of a target validatorStake delegation engenders proportional sharing of emission-derived rewards in the form of the so-called stake rewards. They are taken from the emission-based rewards of the validator (and are therefore conditioned on his performance) in accordance with the delegator's share in the total stake, less the validator-specific fee.
[22] = ƒ([82], validator_fee)
validator_fee
— the fee level configured by the target validator