Certainly! The field of Petri nets encompasses a wide range of concepts that describe the characteristics and behaviors of systems modeled by these nets. Let's explore each of the concepts you've listed by proposing opposite and more general concepts, along with brief explanations.

### 1. Source Place

- **Opposite Concept:** *Sink Place*. A **sink place** is the terminus for tokens within a Petri net, where tokens can accumulate but are not used to enable transitions anymore, contrasting with a source place that generates tokens without consuming them.
- **More General Concept:** *Place*. The concept of a **place** is more general as it encompasses both source places, sink places, and intermediate places in a Petri net, representing conditions or resources in the system being modeled.

### 2. Immediate Transition

- **Opposite Concept:** *Timed Transition*. Whereas an immediate transition fires without any delay as soon as its input conditions are met, a **timed transition** incorporates a delay between when it becomes enabled and when it actually fires, therefore introducing a concept of time.
- **More General Concept:** *Transition*. This is a broader category that includes both immediate and timed transitions, representing events that can change the state of the network when they fire.

### 3. Live Transition

- **Opposite Concept:** *Dead Transition*. A **dead transition** is one that can never fire again in the given marking of the Petri net and future reachable markings from this state, indicating a lack of dynamic capability, in contrast to a live transition, which has the potential to fire under some sequence of events.
- **More General Concept:** *Transition Liveness*. The concept of **transition liveness** is more general and examines the capability of transitions to fire across different states of the Petri net, encompassing properties from completely live to dead.

### 4. Bounded Net

- **Opposite Concept:** *Unbounded Net*. An **unbounded net** is one where there's at least one place in the net for which the number of tokens can grow indefinitely, in contrast to a bounded net where there is a finite upper limit on the number of tokens in every place across all reachable markings.
- **More General Concept:** *Net Boundedness*. **Net boundedness** is a broader term evaluating whether a Petri net is bounded or unbounded, thus addressing the general property of the net regarding the limitations on token accumulation.

### 5. Free Choice Net

- **Opposite Concept:** *Non-Free Choice Net*. A **non-free choice net** is characterized by places that have outgoing arcs to transitions where the choice of firing is not solely dependent on the enabling condition of one place but may involve complex conditions and interactions, contrasting with a free choice net where every choice is "free" or independent of other places.
- **More General Concept:** *Petri Net Structure*. The concept of **Petri net structure** encompasses the organizational and relational aspects of places, transitions, and arcs within a Petri net, including characteristics like being a free choice net or other structural classifications, demonstrating the overarching framework of Petri net configurations.

Each opposite concept I've proposed stands in contrast to the characteristics of the original concepts, highlighting different aspects or functionalities within the Petri nets field. Similarly, the more general concepts provide a broader categorization, under which the specific instances (like those you've mentioned) can be understood.